How is dermatitis different from eczema?
Dermatitis is a general term meaning inflammation (-itis) of the skin (derm-). Ezcema is also a general term derived from a Greek word meaning "to boil over."
Dermatitis is an encompassing term -- it includes any inflammation of the skin. It can come from contact with a plant such as poison ivy or from adhesive tape. It can come from a drug, such as penicillin. It can even happen in a person with a family history of allergies, hay fever and asthma; in that case we call it eczema. We also call it atopic dermatitis. In atopic dermatitis we think that the person may be genetically missing a substance in the outer layers of the skin that helps retain moisture.
If the cause of dermatitis can be identified and eliminated, as in the case of poison ivy or adhesive or a drug, of course that is the first thing to be done. But in eczema the causes are not apparent. We are aware of things that aggravate eczema such as wool, heat and perspiration, but only rarely do we know exactly what has caused eczema.
Dermatitis and eczema are treated by calming the skin. Often an anti-inflammatory agent such as steroid (cortisone) cream is used. Mild cortisone creams should be used on the face or in creases (hydrocortisone cream is an example). Stronger cortisone creams may be used on other areas of the body. If itching is a factor, oral antihistamines can often help. An over-the-counter antihistamine called diphenhydramine can help control the itch.
Skin that is inflamed should not be exposed to hot water or soap, which can further irritate and dry the skin. A thin layer of cortisone cream should be applied in a downward direction to the affected areas. Then moisturizing creams may be applied.
There is a new agent available for the treatment of eczema that is not a steroid but a topical immunomodulator called protopic. It should be applied sparingly to dry skin and may cause stinging or burning the first few days it is applied.