Dermatitis is inflammation of the upper layers of the skin, causing itching, blisters, redness, swelling, and often oozing, scabbing, and scaling.
Known causes include dry skin, contact with a particular substance, certain drugs or medications, and varicose veins.
Typical symptoms include a red itchy rash, scaling, open sores, oozing, and crusting.
The diagnosis is typically based on symptoms and confirmed by results of skin tests or skin samples or the presence of suspected drugs or irritants.
Avoiding known irritants and allergens (substances that cause an allergic reaction) reduces the risk of dermatitis.
Treatment depends on the cause and the specific symptoms.
(See also Itching.)
Dermatitis is a broad term covering many different disorders that all result in a red, itchy rash. Eczema is synonymous with dermatitis but is often used to mean atopic dermatitis. Skin infections, such as fungal infections, are not classified as dermatitis.
Some types of dermatitis affect only specific parts of the body (such as contact dermatitis, including poison ivy; nummular dermatitis; stasis dermatitis; lichen simplex chronicus; seborrheic dermatitis; and hand and foot dermatitis), whereas others can occur anywhere (such as atopic dermatitis).
Some types of dermatitis have a known cause (such as allergic contact dermatitis), whereas others do not (such as nummular dermatitis).
Chronic dermatitis persists over a long period of time. The hands are particularly vulnerable to chronic dermatitis, because the hands are in frequent contact with many foreign substances. Chronic dermatitis can have many different causes. Chronic scratching and rubbing because of itching often results in thickening of the skin (lichenification).
Symptoms of Dermatitis
Dermatitis causes
Redness
Itching
Scaling
Swelling
Oozing
Crusting
Blisters (sometimes)
Thickening of skin, or lichenification (in chronic dermatitis)
Chronic dermatitis often results in thickening of skin and cracks in the skin. Any type of dermatitis may be complicated by an infection.
Diagnosis of Dermatitis
A doctor's examination
Skin or blood tests or both
Sometimes biopsy
Doctors base the diagnosis of dermatitis on the person's symptoms and on what the rash looks like and where it appears on the body. Doctors try to determine whether the person has come in contact with an irritating substance, has an allergy, or has an infection.
To confirm the diagnosis, doctors may do certain tests, such as a patch test or blood tests. They may take samples of skin and send them to a laboratory (biopsy).
Prevention of Dermatitis
Avoidance of triggers
To reduce the risk of dermatitis, people should avoid known allergens and irritating substances (triggers).
Treatment of Dermatitis
Supportive care (such as moisturizers and dressings, and antihistamines for itching)
Topical corticosteroids or other immunosuppressive (medications that decrease the immune system responses) creams or ointments
Sometimes antibiotics
Sometimes systemic (bodywide) immunosuppressive medications or injections
Sometimes ultraviolet (UV) light therapy
Dermatitis treatment depends on the cause and the specific symptoms. For example, doctors may give people moisturizers or corticosteroid creams to relieve itching. Some people may be given antibiotics by mouth or injections of certain medications. Some people may be helped by exposure to ultraviolet light (phototherapy).
