Skin Disorders - Dermatitis

Basic Information

Dermatitis describes a skin disorder usually typified by superficial scaling, redness papules and swelling. These skin disorders are associated with unknown factors and many of them are difficult to diagnose because of the similarities among the different rashes.

Atopic dermatitis (atopic eczema), seborrheic dermatitis (which includes common dandruff of the scalp) and psoriasis are among the major dermatoses that are endogenous (malfunctioning skin). These disorders are inclined to spontaneous worsening (or remission) which may be due to irritants such as soap, detergents or abrasive cleaners. These external factors influencing dermatitis are described as exogenous. Most dermatoses, including those named above, are thought to result from a combination of endogenous and exogenous factors.

Dermatitis also refers to skin rashes whose origin is known and result from exposure to environmental substances. Poison oak or poison ivy would be an example of this sort of rash. This kind of dermatitis is called allergic contact dermatitis. Contact dermatitis is quite common. It can be caused by an allergy to or irritation stemming from the skin coming into contact with certain clothing or materials such as wool. It is estimated that over half of Americans have experienced some form of contact dermatitis.

Atopic Dermatitis Or Atopic Eczema Or Eczema

Eczema is an itchy rash that seems to affect those patients whose skin is sensitive by nature and prone to irritation. The highest incidence is in young children, with over 85% of patients developing this rash before 5 years of age. It usually disappears or "clears up" but it can return years later. If it does reappear, it usually does so on the hands. Also over 50% of children who have atopic dermatitis develop eczema by the time they are 13. Eczema is sometimes called a "constitutional skin defect" -- it is known to run in families and is neither contagious nor curable. It affects those patients with dry skin who are sensitive to certain exogenous factors (such as clothing, soaps, etc.) And whose condition may be adversely affected by hot or cold weather.

Psoriasis

This is a chronic, itchy skin disorder that also runs in families -- the lesions are slightly raised, whitish scales with pink or reddish margins. It is a chronic condition that affects up to 2% of the U.S. population. Men and women seem to be equally affected, though the African American and Native American population, as well as the Asian population, are less affected than whites. Like eczema psoriasis usually begins in childhood and can re-appear chronically in adulthood. It can appear at the site of a physical disturbance (sunburn or intense scratching or minor injury). Stress or infections can also activate this chronic disorder, an episode of which can last for a few days up to a few months. The psoriasis can be mild to quite severe and is not contagious, nor is it curable, only controllable.

Seborrheic Dermatitis

This is a genetically acquired scaling rash that is harmless and quite common. We are familiar with seborrheic dermatitis of the scalp -- it is called dandruff. Seborrheic dermatitis can also appear on:

the eyebrows;
the earsl;
the armpits;
the groin;
the chest (patches);
the back (patches).

This rash runs in families, is not contagious and its cause is unknown. Stress appears to contribute to its appearance, but it can be chronic, coming and going at any age, getting better or worse seemingly at will, with no known factor to point to.

Contact Dermatitis

As discussed above, contact dermatitis is the result of exposure to environmental substances and can be divided into two groups:

Irritant contact dermatitis
soaps, detergents;
shampoos and hair tints (beauticians);
ragweed;
rubber -- rubber gloves (medical);
cement (construction workers);
certain clothing.

Allergic contact dermatitis:

poison oak;
poison sumac;
poison ivy;

also, but less frequent:

formaldehyde (cosmetics);
nickel (jewelry).

With irritant contact dermatitis, dry fissures and swelling or inflammation occurs. Allergic contact dermatitis can present with blisters whose pattern is usually asymmetric. One-fifth of dermatitis cases in young children are caused by allergic contact dermatitis.

Symptoms

Atopic dermatitis

lesions are a result of itching;
lesions appear typically on the neck, face, bend of the knees;
dryness, blistering and oozing;
in adults, redness and scaling in the hands is common.

Psoriasis

areas of skin grows faster than normal so red, scaling patches are formed;
the rash is most often found on the scalp, elbows and knees;
forms sharp, demarcated, often crusted plaques.

Seborrheic dermatitis

scaling, sometimes itching rash (see basic information section for description of parts of the body where the rash is most likely to appear);
dandruff -- on the scalp -- forms a diffuse, scaling area with mild pinkness.

Contact dermatitis

irritant contact dermatitis can result in dryness, swelling and fissuring of the area;
allergic contact dermatitis can present with asymmetric lesions that may itch, burn and sting.

Diagnosis/Treatment

Dermatitis

Diagnosis is made in the office by your health care provider and, if necessary, also by a referral to an experienced dermatologist who can identify the rash by sight, take a family medical history (looking for signs of eczema or allergic rhinitis as well as genetic probability), and who can also probe for signs of external exposures to irritating substances. Clinically taken altogether, these "clues" can form a whole picture and reveal the type of dermatitis that you have. Laboratory tests or skin biopsies are rarely done and generally not useful.

Contact dermatitis

Besides taking a family medical history and making a physical examination, your health care provider and/or dermatologist may do patch testing for allergic contact dermatitis, especially when an inflammation persists after appropriate treatment. Also if there is a suspicion of a secondary infection, a gram stain and culture may be taken.

Atopic dermatitis (eczema) can be treated by topical measures -- by topical corticosteroids in most cases, intermediate-potency steroids in more severe cases and potent corticosteroids in the most severe cases. Oral antihistamines may help control itching and the sedating effect of the medication may help prevent scratching during sleep. Dry skin may be helped by emollients.

Your health care provider may discuss how to avoid factors that could alleviate or worsen your condition (i.e. contact with irritating substances, sudden changes in the temperature, allergies, certain foods). And remember -- atopic dermatitis in 60% of patients who develop eczema in childhood will have recurring episodes as adults. Topical corticosteroids will be an effective treatment for well over 90% of patients. Do not try to treat yourself with homemade ointments -- you could make the condition worse. Work in tandem with your health care provider and/or dermatologist for best results. If topical corticosteroids are not effective a tar-oil bath or lotions containing crude tar oil may be recommended.

Psoriasis is also treated by topical corticosteroids. Tar products may also be used. Anthralin may also be used to control the rapid growth of skin cells -- it is a strong medicine that can irritate the skin and should be used only under the direction and supervision of your health care provider. It has proven effective in long term improvement of psoriasis. Ultraviolet light therapy is another option in treatment of this skin disorder.

Remember psoriasis is not contagious and in and of itself is not dangerous, only itchy, uncomfortable and unattractive. But it is quite common, with an estimated 1 in 40 Americans affected by it, but in almost all cases it is controllable.

Treatment for seborrheic dermatitis relies as well on corticosteroids, tar and antifungal agents while emphasizing control, not cure. Dandruff can best be controlled by frequently washing your hair with medicated shampoos. Dandruff is harmless and the myth that it causes baldness is just that -- a myth. Cortisone creams are usually effective in controlling seborrheic dermatitis on other parts of the body.

With contact dermatitis avoidance of irritants is the key. In severe cases oral corticosteroids are often recommended. In cases of allergic contact dermatitis -- for instance if you have poison ivy, poison sumac or poison oak dermatitis -- washing off the irritant with mild soap or even plain water is generally beneficial. Cold compacts applied to the blistered area for half hour periods five or six times a day for the first three days after exposure is helpful as well. Most cases resolve within 2 months, sometimes within 2 weeks as long as re-exposure does not occur.

If you have any questions or concerns about or if you have a skin disorder, please see your health care provider.

ADDITIONAL INFORMATION:

American Academy of Dermatology 847-330-0230