LESSON №5
1. PRACTICAL SKILLS OF HISTORY TAKING OF PATIENT WITH SKIN DISEASE. ASSESSMENT – 2. DEFENSE OF CASE HISTORY.
2. TUBERCULOSIS OF THE SKIN.
EXAMINATION OF PATIENT WITH SKIN DISEASES
1. Skin exam is not separate from the rest of the physical examination
2. Examine the patient in good lighting
http://www.aad.org/skin-conditions/about-dermatology
KNOWLEDGE BASE
Anatomy of skin
Histology of skin
Normal aging changes
o Stratum corneum maintained but rete ridges flatten
o Dermis thins by 20%; 50%v decline in epidermal turnover
o 10-20% per decade loss of in melanocytes from age 30
o Slowed wound healing
Primary lesions of skin
Secondary lesions of skin
Primary diseases of skin
Systemic diseases affecting skin
Pathology of skin lesions
1. PATIENT’S PASSPORT.
2. PATIENT’S COMPLAINTS:
Skin rashes;
Subjective sensation, which are connected with skin rashes:
v itch of the skin;
v burning;
v pain;
v skin weeping;
v dryness of the skin;
v feeling of a tense skin;
v weakness, weight loss, fever etc.
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Symptoms |
Itching |
Pain |
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Diurnal variation |
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Nocturnal T |
Scabies |
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Daytime t |
Photodermatosis |
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Seasonal |
(because of sun exposure) |
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Summer aggravation |
Fungal infections |
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Insect bites |
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Polymorphic light eruption |
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Winter aggravation |
Ichthyosis |
Systemic sclerosis |
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Psoriasis |
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Scabies (because of crowding) |
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Chilblains |
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Precipitated by |
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Exercise |
Cholinergic urticaria |
Intermittent claudication |
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Cold |
Cold urticaria |
Raynauds phenomenon |
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Associated features |
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Rash |
Drug Rash |
Herpes zoster |
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Wkmk |
Urticaria |
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Cyanosis |
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Raynaud’s phenomenon |
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Gangrene |
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+ |
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H\popigmented lesion |
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HISTORY OF PRESENT ILLNESS:
Possible etiology of the disease ( according patient’s mind).
Duration of the disease:
Acute (< 2 month)
Chronic (> 2 month):
v course of a disease;
v previous treatment and effect from it;
v family history:
Family history is vital in patients with:
v • Genetic disorders like ichthyosis, neurofibromatosis and epidermolysis bullosa.
v Infections and infestations e.g., scabies.
v Families exposed to similar environmental influences may also develop same disease e.g.
LIFE HISTORY ( PAST HISTORY)
Past medical history.
Associated inner diseases.
Harmful habit.
Occupational hazards.
Allergological history.
Allergic reactions to medication
http://www.nlm.nih.gov/medlineplus/ency/imagepages/19329.htm
A true allergy to a medication is different than a simple adverse reaction to the drug. The allergic reaction occurs when the immune system, having been exposed to the drug before, creates antibodies to it. On subsequent exposure to the drug these antibodies cause release of histamines. If severe, this reaction can result in a life-threatening situation known as anaphylactic shock.
OBJECTIVE INVESTIGATION:
TECHNIQUES OF EXAMINATION
http://www.nlm.nih.gov/medlineplus/skinhairandnails.html
1. Inspect and palpate
Inspect and palpate skin for the following:
Skin inspection
The only way to know if your skin is healthy and intact is to look at it regularly. In areas where sensation (feeling) is decreased, skin inspection is essential and should become a habit. Plan it as a part of your regular daily routine, during a time when you are undressed anyway — such as after a shower, before dressing in the morning or after undressing in the evening. Daily skin inspection is necessary.
If you are unable to see some parts of your body, use a mirror or teach another person to check your skin for you. Long handled mirrors and other specially designed mirrors are available. Check all of your bony prominences, or areas where the bones protrude slightly below the skin (see illustrations below for the locations and names of these areas).
http://sci.washington.edu/info/pamphlets/skin_2.asp
Color: Contrast with color of mucous membrane.
Texture
Turgor: Lift a fold of skin and note the ease with which it moves (mobility) and the speed with which it returns into place
Moisture
Pigmentation
Lesions
Hair distribution
Warmth: Feel with back of your hand.
COLOR
Patients ofteotice change in color before physician
Look for increased pigmentation, loss of pigmentation
Look for redness, pallor, cyanosis, and yellowing:
v Red color of oxyhemoglobin best assessed at fingertips, lips, and mucous membranes in dark-skinned people, palms and soles.
v For central cyanosis, look in lips, oral mucosa, and tongue.
v Jaundice – sclera.
MOISTURE
Dryness, sweating, and oiliness
DRY SKIN is common. It can occur at any age and for many reasons. Using a moisturizer often helps repair dry skin.
http://www.aad.org/skin-conditions/dermatology-a-to-z/dry-skin
The signs (what you see) and symptoms (what you feel) of dry skin are:
Rough, scaly, or flaking skin
Itching
Itching Itching is a tingling or irritation of the skin that makes you want to scratch the affected area. Itching may occur all over the whole body or only in one location.
http://www.nlm.nih.gov/medlineplus/ency/article/003217.htm
Considerations
Itching may occur all over the whole body (generalized) or only in one location (localized).
Causes
There are many causes of itching, including:
Aging skin
Contact dermatitis (poison ivy or poison oak)
Contact irritants (such as soaps, chemicals, or wool)
Parasites such as pinworm, body lice, head lice, and pubic lice
Rashes (may or may not itch)
Superficial skin infections such as folliculitis and impetigo
Generalized itching may be caused by:
Childhood infections (such as chickenpox or measles)
Kidney disease
Liver disease with jaundice
Pregnancy
Reactions to medications and substances such as antibiotics (penicillin, sulfonamides), gold, griseofulvin, isoniazid, opiates, phenothiazines, or vitamin A
Home Care
For persistent or severe itching, see your health care provider for a diagnosis and treatment instructions.
In the meantime, you can take some steps to help deal with the itch:
Avoid scratching or rubbing the itchy areas. Keep fingernails short to avoid damaging the skin from scratching. Family members or friends may be able to help by calling attention to your scratching.
Wear cool, light, loose bedclothes. Avoid wearing rough clothing, particularly wool, over an itchy area.
Take lukewarm baths using little soap and rinsing thoroughly. Try a skin-soothing oatmeal or cornstarch bath.
Apply a soothing lotion after bathing to soften and cool the skin.
Use moisturizer on the skin, particularly in the dry winter months. Dry skin is a common cause of itching.
Apply cold compresses to an itchy area.
Avoid prolonged exposure to excessive heat and humidity.
Take part in activities that distract from the itching during the day and make you tired enough to sleep at night.
Try over-the-counter oral antihistamines such as diphenhydramine (Benadryl), but be aware of possible side effects such as drowsiness.
Try over-the-counter hydrocortisone cream on itchy areas.
Gray, ashy skin in people with dark skin
Cracks in the skin, which may bleed if severe
Chapped or cracked lips
When dry skin cracks, germs can get in through the skin. Once inside, germs can cause an infection. Red, sore spots on the skin may be an early sign of an infection.
TEMPERATURE
http://www.nlm.nih.gov/medlineplus/images/boydoctor.jpg
v Use back of fingertips
v Identify warmth or coolness of skin
TEXTURE
Roughness or smoothness
MOBILITY AND TURGOR
v Lift fold of skin
v Note ease with which it lifts up (mobility) and speed with which it returns to place (turgor)
Changes in face with age
http://www.nlm.nih.gov/medlineplus/ency/imagepages/8665.htm
Facial skin tends to wrinkle with age.
HAIR
http://www.nlm.nih.gov/medlineplus/ency/imagepages/8669.htm
v Inspect and palpate
v Note quantity, distribution, and texture
Hair color is caused by a pigment (melanin) that is produced by the hair follicle. With aging, the follicle produces less melanin.
Aged hair follicles are no longer as prepared for new hair growth.
Hair follicle
Each hair sits in a cavity in the skin called a follicle. Over time the follicle can shrink causing the hair to become shorter and finer. Ordinarily, the hair should grow back but in men who are balding the very small follicle ceases to grow any hair. The cause of baldness is not well understood, but is thought to be related to the genes and male sex hormones of the individual.
http://www.nlm.nih.gov/medlineplus/ency/imagepages/19647.htm
NAILS
Nail abnormalities
http://www.nlm.nih.gov/medlineplus/ency/article/003247.htm
Nail abnormalities are problems with the color, shape, texture, or thickness of the fingernails or toenails.
Just like the skin, the fingernails tell a lot about your health.
Beau’s lines are depressions across the fingernail. These lines can occur after illness, injury to the nail, and when you are malnourished.
Brittle nails are often a normal result of aging. However, they also may be due to certain diseases and conditions.
Brittle nails
Like the skin, the fingernails are a reflection of a person’s state of health. Low levels of zinc and iron as well as thyroid problems can cause brittle nails. However, brittle nails are often a normal result of aging.
http://www.nlm.nih.gov/medlineplus/ency/imagepages/9136.htm
Koilonychia is an abnormal shape of the fingernail. The nail has raised ridges and is thin and curved inward. This disorder is associated with iron deficiency anemia.
Leukonychia is white streaks or spots on the nails.
Pitting is the presence of small depressions on the nail surface. Sometimes the nail is also crumbling. The nail can become loose and sometimes falls off.
Ridges are tiny, raised lines that develop across or up and down the nail.
CAUSES
Injury:
Crushing the base of the nail or the nail bed may cause a permanent deformity.
Chronic picking or rubbing of the skin behind the nail can cause a washboard nail.
Long-term exposure to moisture or nail polish can cause nails to peel and become brittle.
Infection:
Fungus or yeast cause changes in the color, texture, and shape of the nails.
Bacterial infection may cause a change in nail color or painful areas of infection under the nail or in the surrounding skin. Severe infections may cause nail loss.
Viral warts may cause a change in the shape of the nail or ingrown skin under the nail.
Certain infections (especially of the heart valve) may cause red streaks in the nail bed ( splinter hemorrhages).
Diseases:
Disorders that affect the amount of oxygen in the blood (such as abnormal heart anatomy and lung diseases including cancer or infection) may cause clubbing.
Clubbed fingers
Clubbed fingers is a symptom of disease, often of the heart or lungs which cause chronically low blood levels of oxygen. Diseases which cause malabsorption, such as cystic fibrosis or celiac disease can also cause clubbing.
http://www.nlm.nih.gov/medlineplus/ency/imagepages/18127.htm
Kidney disease can cause a build-up of nitrogen waste products in the blood, which can damage nails.
Liver disease can damage nails.
Thyroid diseases such as hyperthyroidism or hypothyroidism may cause brittle nails or splitting of the nail bed from the nail plate (onycholysis).
Severe illness or surgery may cause horizontal depressions in the nails (Beau’s lines).
Psoriasis may cause pitting, splitting of the nail plate from the nail bed, and chronic destruction of the nail plate (nail dystrophy).
Other conditions that can affect the appearance of the nails include systemic amyloidosis, malnutrition, vitamin deficiency, and lichen planus.
Skin cancers near the nail and fingertip can distort the nail. Subungal melanoma is a potentially deadly cancer that will normally appear as a dark streak down the length of the nail.
Darkening of the cuticle associated with a pigmented streak may a sign of an aggressive melanoma.
Prevention
Do not bite, pick, or tear at your nails (in severe cases, some people may need psychological help or encouragement to stop these behaviors).
Keep hangnails clipped.
Wear shoes that don’t squeeze the toes together, and always cut the nails straight across along the top.
To prevent brittle nails, keep the nails short and avoid nail polish. Use an emollient (skin softening) cream after washing or bathing.
Alternative Names
Beau’s lines; Fingernail abnormalities; Spooails; Onycholysis; Leukonychia; Koilonychia; Brittle nails
Aging changes iails
http://www.nlm.nih.gov/medlineplus/ency/imagepages/8671.htm
The nails change with aging, growing more slowly, and becoming dull and brittle. The color may change from translucent to yellowed and opaque. Nails, especially toenails, may become hard and thick and ingrown toenails may be more common. The tips of the fingernails may fragment. Sometimes, lengthwise (longitudinal) ridges will develop in the fingernails and toenails. This can be a normal aging change. However, some nail changes can be caused by infections, nutritional problems, trauma, and other problems.
DISTRIBUTION OF LESIONS
Examination of Lesions
Configuration
Annular (rings)
Grouped
Linear
Arciform (bow-Shaped)
Diffuse
CONFIGURATION
Skin lesions in context
v Whenever you see a skin lesion, look it up in a well-illustrated textbook of dermatology
v To arrive at a dermatologic diagnosis, consider the type of lesions, location, and distribution, along with the patient’s history and physical
Examples of skin distribution
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HERPES INFECTION
VITILIGO
PSORIASIS
General blood analysis
http://www.nlm.nih.gov/medlineplus/ency/presentations/100152_1.htm
The complete blood count (CBC) is a screening test, used to diagnose and manage numerous diseases. It can reflect problems with fluid volume (such as dehydration) or loss of blood. It can show abnormalities in the production, life span, and destruction of blood cells. It can reflect acute or chronic infection, allergies, and problems with clotting.
The CBC test isolates and counts the 7 types of cells found in the blood: neutrophil, eosinophil, basophil, red blood cell, lymphocyte, monocyte, and platelet.
Stool test for parasites
Testing the Stool for Ova and Parasites
http://kidshealth.org/parent/general/sick/labtest8.html#
Stool may be tested for the presence of parasites and ova (the egg stage of a parasite) if a child has prolonged diarrhea or other intestinal symptoms. Sometimes, the doctor will collect two or more samples of stool to successfully identify parasites. If parasites — or their eggs — are seen when a smear of stool is examined under the microscope, the child will be treated for a parasitic infestation. The doctor may give you special collection containers that contain chemical preservatives for parasites.
1. Skin lesion biopsy
http://www.nlm.nih.gov/medlineplus/ency/article/003840.htm
A skin lesion biopsy is the removal of a piece of skin to diagnose or rule out an illness.
How the Test is Performed
There are several ways to do a skin biopsy. Most procedures can be easily done in outpatient medical offices or your doctor’s office.
Which procedure you have depends the location, size, and type of lump or sore. You will receive some type of numbing medicine (anesthetic) before any type of skin biopsy.
Types of skin biopsies include:
Shave biopsy
Punch biopsy
Excisional biopsy
Incisional biopsy
The shave biopsy is the least invasive of all three techniques. Your doctor will remove the outermost layers of skin. You will not need stitches.
Punch biopsies are most often used for deeper skin spots or sores. Your doctor removes a small round piece of skin (usually the size of a pencil eraser) using a sharp, hollow instrument. If a large sample is taken, the area may be closed with stitches.
An excisional biopsy is done to remove the entire lesion. A numbing medicine is injected into the area. Then the entire lump, spot, or sore is removed, going as deep as needed to get the whole area. The area is closed with stitches. Pressure is applied to the area to stop any bleeding. If a large area is biopsied, a skin graft or flap of normal skin may be used to replace the skin that was removed.
An incisional biopsy takes a piece of a larger growth for examination. The area is injected with a numbing medicine. A piece of the growth is cut and sent to the lab for examination. You may have stitches, if needed. The rest of the growth can be treated after the diagnosis is made.
Why the Test is Performed
Your doctor may order a skin biopsy if you have signs or symptoms of:
Chronic or acute skin rashes
Noncancerous (benign) growths
Skin cancer
Other skin conditions
Normal Results
Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
The test may reveal skin cancers or noncancerous (benign) conditions. Bacteria and fungi can be identified. The test may also reveal some inflammatory diseases of the skin. Once the diagnosis is confirmed with the biopsy, a treatment plan is usually started.
Risks
Risks may include:
Infection
Scar (keloids)
You will bleed slightly during the procedure. Tell your doctor if you have a history of bleeding problems.
Considerations
Fluid-filled sores or growths may be examined by skin lesion aspiration instead of skin lesion biopsy.
Alternative Names
Punch biopsy; Shave biopsy; Skin biopsy; Biopsy – skin.
http://www.nlm.nih.gov/medlineplus/ency/imagepages/9894.htm
Mucosal skin biopsy is the removal of a small piece of skin or mucous membrane. The sample can be retrieved in several ways: a shave biopsy (scraping or shaving a thin layer), a punch biopsy (using a needle or punch to obtain a small, but deeper, sample), or an excision of tissue (cutting to remove a piece of tissue). The sample is sent to the laboratory to isolate and identify organisms that cause infection.
2. Culture and sensitivity (viral, bacteria, fungi)
http://www.nlm.nih.gov/medlineplus/ency/imagepages/10027.htm
A viral lesion culture is performed to confirm herpes simplex virus present in a skin lesion. The specimen is collected by scraping the suspected skin lesion or aspirating fluid from the lesion. Results are available within 16 hours to 7 days of receipt of the specimen, depending on the culture method used.
This microscopic film shows a fluorescent stain of Candida. Candida is a yeast (fungus) that causes mild disease, but in immunocompromised individuals it may cause life-threatening illness. (Image courtesy of the Centers for Disease Control and Prevention.)
http://www.nlm.nih.gov/medlineplus/ency/imagepages/1053.htm
3.Immunofluorescence
A portion of the skin biopsy can be frozen in liquid nitrogen for direct immunofluorescence (IF). This involves visualising antigens that are present in skin by identifying them with fluorescein-labelled antibodies. Similarly, indirect immunofluorescence can identify circulating antibodies in the serum by an additional step of adding the serum to a section of normal skin or other substrate. Immunofluorescence plays a major role in the diagnosis of the autoimmune bullous disorders.
4. Allergy testing – skin
http://www.nlm.nih.gov/medlineplus/ency/article/003519.htm
http://www.nlm.nih.gov/medlineplus/ency/imagepages/19344.htm
Allergy skin tests are tests used to find out which substances cause a person to have an allergic reaction.
How the Test is Performed
There are three common methods of allergy skin testing.
The skin prick test involves:
Placing a small amount of substances that may be causing your symptoms on the skin, most often on the forearm, upper arm, or back.
Then, the skin is pricked so the allergen goes under the skin’s surface.
The health care provider closely watches the skin for swelling and redness or other signs of a reaction. Results are usually seen within 15-20 minutes.
Several allergens can be tested at the same time.
The intradermal skin test involves:
Injecting a small amount of allergen into the skin.
Then the health care provider watches for a reaction at the site.
This test is more likely to be used to find out if you are allergic to something specific, such as bee venom or penicillin.
Patch testing is a method to diagnose the cause of skin reactions that occur after the substance touches the skin.
Possible allergens are taped to the skin for 48 hours.
The health care provider will look at the area in 72 – 96 hours.
How to Prepare for the Test
Before any allergy testing, the health care provider will ask questions about:
Illnesses
Where you live and work
Lifestyle
Foods and eating habits
Allergy medicines can change the results of skin tests. Your doctor will tell you which medicines to avoid and when to stop taking them before the test.
How the Test Will Feel
Skin tests may cause very mild discomfort when the skin is pricked.
You may have symptoms such as itching, a stuffy nose, red watery eyes, or a skin rash if you allergic to the substance in the test.
Rarely, people can have a whole-body allergic reaction (called anaphylaxis), which can be life threatening. This usually only occurs with intradermal testing. Your health care provider will be prepared to treat this serious response.
Why the Test is Performed
Allergy tests are done to determine what substances are causing your allergy symptoms.
Your doctor may order allergy skin tests if you have:
Hay fever (allergic rhinitis) and asthma symptoms that are not well controlled with medicine
Hives and angioedema
Food allergies
Skin rashes (dermatitis), in which the skin becomes red, sore, or swollen after contact with the substance
Penicillin allergy*
Venom allergy
*NOTE: Allergies to penicillin and closely related medicines are the only drug allergies that can be tested using skin tests. Skin tests for allergies to other drugs can be dangerous.
The prick skin test may also be used to diagnose food allergies. Intradermal tests are not used to test for food allergies because of high false-positive results and the danger of causing a severe allergic reaction.
Normal Results
A negative test result means there were no skin changes in response to the allergen. This negative reaction most often means that you are not allergic to the substance.
Rarely, a person may have a negative allergy test and still be allergic to the substance.
What Abnormal Results Mean
A positive result means you reacted to a substance. Your health care provider will see a red, raised area called a wheal.
Often, a positive result means the symptoms you are having are due to exposure to that substance. In general, a stronger response means you are more sensitive to the substance.
People can have a positive response to a substance with allergy skin testing, but not have any problems with that substance in everyday life.
Skin tests are usually accurate. However, if the dose of allergen is large, even people who are not allergic will have a positive reaction.
Your health care provider will consider your symptoms and the results of your skin test to suggest lifestyle changes you can make to avoid substances that may be causing your symptoms.
Alternative Names
Patch tests – allergy; Scratch tests – allergy; Skin tests – allergy; RAST test
One of the most common methods of allergy testing is the scratch test or skin prick test. The test involves placing a small amount of the suspected allergy-causing substance (allergen) on the skin (usually the forearm, upper arm, or the back), and then scratching or pricking the skin so that the allergen is introduced under the skin surface. The skin is observed closely for signs of a reaction, which usually includes swelling and redness of the site. With this test, several suspected allergens can be tested at the same time, and results are usually obtained within about 20 minutes.
PRICK TESTS
http://www.nlm.nih.gov/medlineplus/ency/imagepages/19345.htm
http://www.nlm.nih.gov/medlineplus/ency/imagepages/8703.htm
Intradermal allergy testing is another method of skin testing to help determine whether an individual is allergic to a specific allergen. The test involves injection of a small amount of the suspected allergen under the surface of the skin. After about 20 minutes the area is examined for a reaction at the site. A typical reaction looks like a small hive with swelling and redness. The intradermal test is more sensitive than the skin prick test and can usually provide more consistent results.
Allergic reaction is a sensitivity to a specific substance, called an allergen, that is contacted through the skin, inhaled into the lungs, swallowed or injected. The body’s reaction to an allergen can be mild, such as a localized rash, or life-threatening, such as anaphylactic shock.
The RAST (Radioallergosorbent test) is a laboratory test performed on blood. It tests for the amount of specific IgE antibodies in the blood which are present if there is a “true” allergic reaction.
http://www.nlm.nih.gov/medlineplus/ency/imagepages/19334.htm
5. Skin Scrapings
Grattage test and Auspitz sign:
Step A: Gently scrape the lesion with a glass slide. This
accentuates the silvery scales (Grattage test positive).
Scrape off all the scales.
Step B: As you continue to scrape the lesion, a glistening
white, adherent membrane appears.
Step C: On removing the membrane, punctate bleeding
points become visible.
Scrapings for Scabies Mite
The presence of a burrow is diagnostic of scabies. In many patients, however, the burrow may not be visible. In a burrow, the mite appears as a black (grey) dot at the end of the burrow under a magnifying lens. The dot is picked up with a sterile needle and examined under a microscope. If the burrow is not visible, doubtful lesions are scraped and scrapings transferred to a glass slide and examined under the microscope.
Skin lesion KOH exam
http://www.nlm.nih.gov/medlineplus/ency/imagepages/9485.htm
The skin lesion KOH exam is a test to diagnose a fungal infection of the skin.
Fungal infections are caused by microscopic organisms (fungi) that can live on the skin. They can live on the dead tissues of the hair, nails, and outer skin layers.
1. How the Test is Performed
The health care provider scrapes the lesion off your skin, using a blunt edge such as the edge of a microscope slide. The scrapings from the skin lesion are placed in liquid containing potassium hydroxide (KOH) and examined under the microscope. KOH destroys all non-fungal cells, which makes it easier to see if there is any fungus present.
2. How to Prepare for the Test
There is no special preparation for the test.
3. How the Test Will Feel
You may feel pressure when the doctor scrapes the lesion off your skin.
4. Why the Test is Performed
This test is done to diagnose a fungal infection of the skin.
5. Normal Results
Normally, there is no fungus.
6. What Abnormal Results Mean
The KOH smear shows fungus, which may be related to ringworm, athlete’s foot, jock itch, or another fungal infection.
7. There is a small risk of bleeding or infection from scraping the lesion.
Alternative Names
Potassium hydroxide examination of skin lesion
6. Tzanck Smear: Made from floor of the erosion (after removing the crust) shows acantholytic cells
Pathogenesis of acantholysis in pemphigus. Note: acantholytic cells have a perinuclear halo.
7. Wood’s Light Examination
This involves irradiation with a UV light source that causes normal skin, particularly dermis, to fluoresce (in the visible light range).
The basis for this is that in the ultraviolet A wavebands used by Wood’s light, pigmentation has a greater degree of absorption than at longer wavebands, resulting in a greater degree of difference in fluorescence between pigmented and depigmented skin.
Wood’s light also enhances the examination of cutaneous pigmentary abnormalities such as in patients with vitiligo, where areas of subtle depigmentation are more easily seen.
http://www.nlm.nih.gov/medlineplus/ency/imagepages/9846.htm
A Wood’s lamp examination is a test that uses ultraviolet light to closely look at the skin.
1. How the Test is Performed
The test is done while you are seated in a dark room, usually in a dermatologist’s office. The health care provider turns on the Wood’s lamp, holds it 4 to 5 inches from the area of skin being studied, and looks for any skin color changes.
You should not look directly into the light.
2. How to Prepare for the Test
No special preparation is needed. If you are treating the area in question with any topical medications, you may wish to skip an application before visiting the doctor.
3. How the Test Will Feel
You will feel nothing during this test.
4. Why the Test is Performed
Your health care provider may perform this test to detect several conditions affecting the skin, including
Bacterial infections
Fungal infections
Skin coloring changes
5. Normal Results
Normally your skin will not shine, or fluoresce, under the ultraviolet light.
6. What Abnormal Results Mean
A Wood’s lamp exam may help your doctor confirm a fungal infection or bacterial infection. Your doctor may also be able to learn what is causing any light- or dark-colored spots on your skin.
7. Risks
There are no risks. Avoid looking directly into the ultraviolet light.
8. Considerations
Do not wash before the test, because that may cause a false-negative result. A room that is not dark enough may also alter results. Other materials may also glow. For example, some deodorants, make-ups, soaps, and even lint may be visible with the Wood’s lamp.
Not all types of bacteria and fungi can be detected with the light.
9. Alternative Names
Black light test; Ultraviolet light test
A Wood’s lamp emits ultraviolet light and can be a diagnostic aid in determining if someone has a fungal or bacterial infection on the skin or scalp. If there is an infection on the area where the Wood’s lamp is illuminating, the area will fluoresce. Normally the skin does not fluoresce, or shine, under ultraviolet light.
http://www.nlm.nih.gov/medlineplus/ency/imagepages/2096.htm
A Wood’s lamp is a light that uses long wave ultraviolet light. When an area of scalp that is infected with tinea (a type of ringworm fungus) is viewed under a Wood’s light, the fungus may glow. This test may be done to detect the presence of a fungal scalp or skin infection.
8. DIASCOPY
A glass slide is pressed firmly on the skin lesion. If a red lesion blanches, it implies that the red color is secondary to blood within the vessels. By contrast, blood outside the vessels, such as that from a bruise or from vacuities, will not blanch.
Success in blanching is a more useful physical sign than failure to blanch.
Glaucomatous lesions a glass slide reveals an appearance commonly referred to as ‘apple jelly nodule’.
9. EPILUMINESCENCE MICROSCOPY (DERMATOSCOPY, DERMOSCOPY)
This refers to surface microscopy using an illuminated lens with oil immersion directly on to the skin’s surface. The presence of oil reduces specular reflection and reduces ‘errors’ due to the different refractive indexes of the various superficial layers of skin.
10.ELECTRON MICROSCOPY
This investigation has played an important role in the diagnosis of some of the rare blistering disorders such as epidermolysis bullosa, although the availability of a range of antibodies to basement membrane zone antigens has in part replaced it.
TUBERCULOSIS OF THE SKIN
Definitions
TB is a disease that spreads person to person through the air. When a person with pulmonary or laryngeal TB coughs or sneezes, droplet nuclei containing M. tuberculosis are expelled in the air. These particles (1-5 microns in diameter) can remain suspended in the air for several hours. A person that inhales these droplet nuclei may become infected.
http://www.nlm.nih.gov/medlineplus/ency/imagepages/1034.htm
Tuberculosis is caused by a group of organisms Mycobacterium tuberculosis, M. bovis, M. africanum and a few other rarer subtypes. Tuberculosis usually appears as a lung (pulmonary) infection. However, it may infect other organs in the body. Recently, antibiotic-resistant strains of tuberculosis have appeared. With increasing numbers of immunocompromised individuals with AIDS, and homeless people without medical care, tuberculosis is seen more frequently today. (Image courtesy of the Centers for Disease Control and Prevention).
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CLASSIFICATION:
Primary inf. : acquired of bacilli for 1st time
Post primary inf. occurs in pt with previous TB or previous BCG vaccine.
A- Localized as lupus vulgaris, scrofuloderma and TB verrucosa cutis.
B- General as miliary TB, in patient with miliary TB & immune suppressed, multiple TB abscess.
C- Tuberculide
1. papulonecrotic tuberculide.
2. Lichen scrofulosorm.
3. Erythema induratum.
1. PRIMARY TB INFECTION [TUBERCULOSIS CHANCRE]
lUPUS VULGARIS
2. Scrofuloderma
3. Tuberculous warts: [tuberculosis verrucosa cutis]
2. Erythema induratum
Diagnosis of skin TB
confirmed either by find the microorganism in culture media or after animal inoculation
polymerase chain reaction technique
presence of acid fast bacilli
history, positive tuberculin test, presence of caseating granuloma on histopathology and therapeutic response to anti TB drugs
Applying the tuberculin skin test
Applying the tuberculin skin test
Applying the tuberculin skin test
Reading the tuberculin skin test
Reading the tuberculin skin test
The right arm represents a positive reaction to PPD (a skin test for tuberculosis protein). The left arm represents a positive reaction to Candida protein. Candida antigen is tested to determine if the individual’s immune system is functioning well; a normal immune system demonstrates a positive reaction.
http://www.nlm.nih.gov/medlineplus/ency/imagepages/2823.htm
1. Who Should Get Tested for TB
TB tests are generally not needed for people with a low risk of infection with TB bacteria.
Certain people should be tested for TB bacteria because they are more likely to get TB disease, including:
People who have spent time with someone who has TB disease
People with HIV infection or another medical problem that weakens the immune system
People who have symptoms of TB disease (fever, night sweats, cough, and weight loss)
People from a country where TB disease is common (most countries in Latin America, the Caribbean, Africa, Asia, Eastern Europe, and Russia)
People who live or work somewhere in the United States where TB disease is more common (homeless shelters, prison or jails, or some nursing homes)
People who use illegal drugs
2. Testing for TB in BCG-Vaccinated Persons
Many people born outside of the United States have been BCG-vaccinated.
People who have had a previous BCG vaccine may receive a TB skin test. In some people, BCG may cause a positive skin test when they are not infected with TB bacteria. If a TB skin test is positive, additional tests are needed.
IGRAs, unlike the TB skin tests, are not affected by prior BCG vaccination and are not expected to give a false-positive result in people who have received BCG.
3. Choosing a TB Test
The person’s health care provider should choose which TB test to use. Factors in selecting which test to use include the reason for testing, test availability, and cost. Generally, it is not recommended to test a person with both a TST and an IGRA.
4. Diagnosis of Latent TB Infection or TB Disease
If a person is found to be infected with TB bacteria, other tests are needed to see if the person has TB disease.
TB disease can be diagnosed by medical history, physical examination, chest x-ray, and other laboratory tests. TB disease is treated by taking several drugs as recommended by a health care provider.
If a person does not have TB disease, but has TB bacteria in the body, then latent TB infection is diagnosed. The decision about treatment for latent TB infection will be based on a person’s chances of developing TB disease.
5. Diagnosis of TB Disease
People suspected of having TB disease should be referred for a medical evaluation, which will include
v Medical history,
v Physical examination,
v Test for TB infection (TB skin test or TB blood test),
v Chest radiograph (X-ray), and
v Appropriate laboratory tests
Basic TB Facts
http://www.cdc.gov/tb/topic/basics/default.htm
1. How TB Spreads
TB is spread through the air from one person to another. The TB bacteria are put into the air when a person with TB disease of the lungs or throat coughs, sneezes, speaks, or sings. People nearby may breathe in these bacteria and become infected.
2. TB is NOT spread by
v shaking someone’s hand
v sharing food or drink
v touching bed linens or toilet seats
v sharing toothbrushes
v kissing
3. Latent TB Infection and TB Disease
Not everyone infected with TB bacteria becomes sick. As a result, two TB-related conditions exist: latent TB infection and TB disease.
4. Latent TB Infection
TB bacteria can live in the body without making you sick. This is called latent TB infection. In most people who breathe in TB bacteria and become infected, the body is able to fight the bacteria to stop them from growing. People with latent TB infection do not feel sick and do not have any symptoms. People with latent TB infection are not infectious and cannot spread TB bacteria to others. However, if TB bacteria become active in the body and multiply, the person will go from having latent TB infection to being sick with TB disease.
5. TB Disease
TB bacteria become active if the immune system can’t stop them from growing. When TB bacteria are active (multiplying in your body), this is called TB disease. People with TB disease are sick. They may also be able to spread the bacteria to people they spend time with every day.
Many people who have latent TB infectioever develop TB disease. Some people develop TB disease soon after becoming infected (within weeks) before their immune system can fight the TB bacteria. Other people may get sick years later when their immune system becomes weak for another reason.
6. Treatment
Treatment for Latent TB Infection
http://www.cdc.gov/tb/topic/treatment/default.htm
People with latent TB infection have TB bacteria in their bodies, but they are not sick because the bacteria are not active. People with latent TB infection do not have symptoms, and they cannot spread TB bacteria to others. However, if TB bacteria become active in the body and multiply, the person will go from having latent TB infection to being sick with TB disease. For this reason, people with latent TB infection are often prescribed treatment to prevent them from developing TB disease. Treatment of latent TB infection is essential for controlling and eliminating TB in the United States.
Because there are less bacteria in a person with latent TB infection, treatment is much easier. Four regimens are approved for the treatment of latent TB infection. The medications used to treat latent TB infection include:
v isoniazid (INH)
v rifampin (RIF)
v rifapentine (RPT)
Certain groups of people (such as people with weakened immune systems) are at very high risk of developing TB disease once infected with TB bacteria. Every effort should be made to begin appropriate treatment and to ensure completion of the entire course of treatment for latent TB infection.
Treatment for TB Disease
TB bacteria become active (multiplying in the body) if the immune system can’t stop them from growing. When TB bacteria are active, this is called TB disease. TB disease will make a person sick. People with TB disease may spread the bacteria to people with whom they spend many hours.
TB disease can be treated by taking several drugs for 6 to 9 months. There are 10 drugs currently approved by the U.S. Food and Drug Administration (FDA) for treating TB. Of the approved drugs, the first-line anti-TB agents that form the core of treatment regimens include:
v isoniazid (INH)
v rifampin (RIF)
v ethambutol (EMB)
v pyrazinamide (PZA)
Regimens for treating TB disease have an initial phase of 2 months, followed by a choice of several options for the continuation phase of either 4 or 7 months (total of 6 to 9 months for treatment).
It is very important that people who have TB disease finish the medicine, taking the drugs exactly as prescribed. If they stop taking the drugs too soon, they can become sick again; if they do not take the drugs correctly, the TB bacteria that are still alive may become resistant to those drugs. TB that is resistant to drugs is harder and more expensive to treat.
Treatment Completion
Treatment completion is determined by the number of doses ingested over a given period of time. Although basic TB regimens are broadly applicable, there are modifications that should be made under special circumstances (such as people with HIV infection, drug resistance, pregnancy, or treatment of children).
Table 1. Basic TB Disease Treatment Regimens
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Preferred Regimen |
Alternative Regimen |
Alternative Regimen |
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Initial Phase |
Initial Phase |
Initial Phase |
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Continuation Phase |
Continuation Phase |
Continuation Phase |
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*EMB can be discontinued if drug susceptibility studies demonstrate susceptibility to first-line drugs.
Note: A continuation phase of once-weekly INH/rifapentine can be used for HIV negative patients who do not have cavities on the chest film and who have negative acid-fast bacilli (AFB) smears at the completion of the initial phase of treatment.
Continuation Phase of Treatment
The continuation phase of treatment is given for either 4 or 7 months. The 4-month continuation phase should be used in the large majority of patients. The 7-month continuation phase is recommended only for three groups: patients with cavitary pulmonary tuberculosis caused by drug-susceptible organisms and whose sputum culture obtained at the time of completion of 2 months of treatment is positive; patients whose initial phase of treatment did not include PZA; and patients being treated with once weekly INH and rifapentine and whose sputum culture obtained at the time of completion of the initial phase is positive.
Treatment Completion
Treatment completion is determined by the number of doses ingested over a given period of time. Although basic TB regimens are broadly applicable, there are modifications that should be made under special circumstances (e.g., HIV infection, drug resistance, pregnancy, or treatment of children).
Treatment for Drug-resistant Tuberculosis
Drug-resistant TB is caused by TB bacteria that are resistant to at least one first-line anti-TB drug. Multidrug-resistant TB (MDR TB) is resistant to more than one anti-TB drug and at least isoniazid (INH) and rifampin (RIF).
Treating and curing drug-resistant TB is complicated. Inappropriate management can have life-threatening results. Drug-resistant TB should be managed by or in close consultation with an expert in the disease.
Drug resistance is proven by drug-susceptibility testing. However, since this testing can take weeks, treatment should be started with an empirical treatment regimen based on expert advice as soon as drug-resistant TB disease is suspected. When the testing results are known, the treatment regimen should be adjusted according to the results. Patients should be monitored closely throughout treatment. Directly observed therapy (DOT) always should be used in the treatment of drug-resistant TB to ensure adherence.
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