Skin

SKIN

DERMATOPHYTOSIS (TINEA) infections are fungal infections caused by dermatophytes - a group of fungi that invade and grow in dead keratin. Several species commonly invade human keratin and these belong to the Epidermophyton, Microsporum and Trichophyton genera. They tend to grow outwards on skin producing a ring-like pattern - hence the term 'ringworm'. They are very common and affect different parts of the body. They can usually be successfully treated but success depends on the site of infection and on compliance with treatment.

Clinical classification is according to site:

  • Scalp - tinea capitis.
  • Feet - tinea pedis.
  • Hands - tinea manuum.
  • Nail - tinea unguium (or onycomyosis).
  • Beard area -tinea barbae.
  • Groin - tinea cruris.

Body including trunk and arms -tinea corporis.

 

PSORIASIS is a common skin condition that changes the life cycle of skin cells. Psoriasis causes cells to build up rapidly on the surface of the skin. The extra skin cells form thick, silvery scales and itchy, dry, red patches that are sometimes painful.

Psoriasis signs and symptoms can vary from person to person but may include one or more of the following:

  • Red patches of skin covered with silvery scales
  • Small scaling spots (commonly seen in children)
  • Dry, cracked skin that may bleed
  • Itching, burning or soreness
  • Thickened, pitted or ridged nails

Swollen and stiff joints

LICHEN PLANUS is a chronic recurrent rash that is due to inflammation. The rash is characterized by small, flat-topped, many-sided (polygonal) bumps that can grow together into rough, scaly plaques on the skin. There may also be a rash in the lining (mucous membranes) of the mouth or vagina.

The cause of lichen planus is unknown. In certain locales, patients with extensive lichen planus seem to be more likely to have a hepatitis C virus infection of the liver. However, it is unclear if this virus is the cause of lichen planus in such situations.

VITILIGO is a pigmentation disorder in which melanocytes (the cells that make pigment) in the skin are destroyed. As a result, white patches appear on the skin in different parts of the body. Similar patches also appear on both the mucous membranes (tissues that line the inside of the mouth and nose) and the retina (inner layer of the eyeball). The hair that grows on areas affected by vitiligo sometimes turns white.

The cause of vitiligo is not known, but doctors and researchers have several different theories. There is strong evidence that people with vitiligo inherit a group of three genes that make them susceptible to depigmentation. The most widely accepted view is that the depigmentation occurs because vitiligo is an autoimmune disease - a disease in which a person's immune system reacts against the body's own tissues. People's bodies produce proteins called cytokines that, in vitiligo, alter their pigment-producing cells and cause these cells to die. Another theory is that melanocytes destroy themselves. Finally, some people have reported that a single event such as sunburn or emotional distress triggered vitiligo; however, these events have not been scientifically proven as causes of vitiligo.

WARTS are small lumps that often develop on the skin of the hands and feet.

Warts vary in appearance and may develop singly or in clusters. Some are more likely to affect particular areas of the body. For example, verrucas are warts that usually develop on the soles of the feet.

Warts are caused by an infection with the human pappiloma virus (HPV).

The virus causes an excess amount of keratin, a hard protein, to develop in the top skin layer (epidermis). The extra keratin produces the rough, hard texture of a wart.

 

ECZEMA

Rather than a specific condition, eczema is a group of unrelated diseases that have a similar appearance. When it is new eczema, the affected skin appears red and elevated with small blisters (vesicles) containing a clear fluid. When the blisters break, the affected skin will weep and ooze. In older eczema, chronic eczema, the blisters are less prominent and the skin is thickened, elevated, and scaling. Eczema almost always is very itchy.

 

Are there different types of eczema? What causes eczema?

There are at least 11 different types of skin conditions that produce eczema. In order to develop a rational treatment plan, it is important to distinguish them. This is often not easy.

  1. Atopic dermatitis: This condition has a genetic basis and is probably most commonly called eczema. Atopic dermatitis tends to begin early in life in those with a predisposition to inhalant allergies but it probably does not have an allergic basis. Characteristically, rashes occur on the cheeks, neck, elbow and knee creases, and ankles. Rarely, a few those with atopic dermatitis can get an extensive herpes simplex infection called "eczema herpeticum."
  2. Irritant dermatitis: This occurs when the skin is repeatedly exposed to toxic substances.
  3. Allergic contact dermatitis: After repeated exposures to the same substance, the body's immune recognition system becomes activated at the site of the next exposure and produces eczema.
  4. Stasis dermatitis: It commonly occurs on the swollen lower legs of people who have poor circulation in the veins of the legs.
  5. Fungal infections: This can produce a pattern identical to many other types of eczema, but the fungus can be visualized with a scraping under the microscope or grown in culture.
  6. Scabies: It's caused by an infestation by the human itch mite and may produce a rash very similar to other forms of eczema.
  7. Pompholyx (dyshidrotic eczema): This is a common but poorly understood condition which classically affects the hands and occasionally the feet by producing an itchy rash composed of tiny blisters (vesicles) on the sides of the fingers or toes and palms or soles.
  8. Lichen simplex chronicus: It produces thickened plaques of skin commonly found on the shins and neck.
  9. Nummular eczema: This is a nonspecific term for coin-shaped plaques of scaling skin most often on the lower legs of older individuals.
  10. Xerotic (dry skin) eczema: When the skin becomes pathologically dry, it will crack and ooze.
  11. Seborrheic eczema: It produces a rash on the scalp, face, ears, and occasionally the mid-chest in adults. In infants, in can produce a weepy, oozy rash behind the ears and can be quite extensive, involving the entire body.

PIGMENTATION means coloring. Skin pigmentation disorders affect the color of your skin. Your skin gets its color from a pigment called melanin. Special cells in the skin make melanin. When these cells become damaged or unhealthy, it affects melanin production. Some pigmentation disorders affect just patches of skin. Others affect your entire body.

If your body makes too much melanin, your skin gets darker. Pregnancy, Addison's disease, and sun exposure all can make your skin darker. If your body makes too little melanin, your skin gets lighter.

ACNE, OR ACNE VULGARIS, is a skin problem that starts when oil and dead skin cells clog up your pores. Some people call it blackheads, blemishes, whiteheads, pimples, or zits. When you have just a few red spots, or pimples, you have a mild form of acne. Severe acne can mean hundreds of pimples that can cover the face, neck, chest, and back. Or it can be bigger, solid, red lumps that are painful (cysts).

Symptoms of acne include whiteheads, blackheads, and pimples. These can occur on the face, neck, shoulders, back, or chest. Pimples that are large and deep are called cystic lesions. These can be painful if they get infected. They also can scar the skin.

To help control acne, keep your skin clean. Avoid skin products that clog your pores. Look for products that say "noncomedogenic" on the label. Wash your skin once or twice a day with a gentle soap or acne wash. Try not to scrub or pick at your pimples. This can make them worse and can cause scars.