Eczema is a term used to describe a group of inflamed skin conditions that result in chronic, relapsing and very itchy rashes. About 15 million people in the United States suffer from some form of eczema, including 10 to 20 percent of all infants. There is no known cause for the condition, but it appears to involve an overactive immune system in the presence of certain materials and often occurs in people susceptible to allergies. Symptoms vary from person to person but often include dry, red, itchy patches on the skin which, when scratched, tend to break out in rashes. Sometimes rashes "bubble up" and ooze; other times they may be more scaly. A common result of excessive scratching is lichenification, the leathery texture caused by skin thickening.
Objects and conditions that trigger itchy eczema outbreaks may include rough or coarse materials touching the skin, excessive heat or sweating, soaps, detergents, disinfectants, fruit and meat juices, dust mites, animal saliva and danders, upper respiratory infections and stress. Avoidance of those triggers is the simplest way to minimize flare-ups.
The first and most critical step in preventing eczema is to restrain yourself from scratching. Moisturizing lotions or creams, cold compresses and nonprescription anti-inflammatory corticosteroid creams and ointments are often helpful. Beyond this, physicians may prescribe corticosteroid medication, antibiotics to combat infection or sedative antihistamines. Phototherapy is a common procedure to reduce rashes, as are tar treatments (though messy). For severe cases, drugs such as cyclosporine A may be recommended. The FDA is currently studying a new class of drugs called topical immunomodulators (TIMs) for the modulation of immune response to reduce eczema flare-ups.
Children and infants often inadvertently worsen their eczema because they cannot control scratching. You can help by applying moisturizer regularly, avoiding sudden temperature changes, keeping rooms free of dust mites, using mild soaps on skin and clothing, and dressing the child in breathable clothing.
Psoriasis is a term that encompasses a group of chronic skin disorders that affect any part of the body from the scalp to the toenails, but most frequently affect the scalp, elbows, knees, hands, feet and genitals. Over seven million men and women in the U.S. of all ages have some form of psoriasis, which may be mild, moderate or severe. In addition, it may be categorized into different types: plaque, pustular, erythrodermic guttate or inverse psoriasis. Most forms involve an itching and/or burning sensation, scaling and crusting of the skin.
Type-specific symptoms include:
- Plaque psoriasis (the most common type): raised, thickened patches of red skin covered with silvery-white scales;
- Pustular psoriasis: pus-like blisters;
- Erythrodermic psoriasis: intense redness and swelling of a large part of the skin surface;
- Guttate psoriasis: small, drop-like lesions;
- Inverse psoriasis: smooth red lesions in the folds of the skin.
While the cause of psoriasis has yet to be discovered, suspected triggers include emotional stress, skin injury, systemic infections and certain medications. There is a possibility that susceptibility to psoriasis is inherited.
Normally the outer layer of skin, which consists of keratinocytes, is replaced unnoticeably, about once a month. This process is faster in people with psoriasis; keratinocytes reach the skin surface too quickly, before they can be properly incorporated into surrounding tissue or even before they are fully mature. As a result, the skin flakes off. This sped-up process is called parakeratosis.
Psoriasis cannot be cured but it can be treated successfully, sometimes for months or years and occasionally even permanently. Treatment depends on the type, severity and location of psoriasis; the patient’s age, medical history and lifestyle; and the effect the disease has on the patient’s general mental health. The most common treatments are topical medications, phototherapy,photochemotherapy (PUVA), and oral or injectable medication (for severe symptoms).