D

Dermatitis

The terms "dermatitis" and "eczema" are often used interchangeably. Dermatitis can be "acute" or "chronic" or both. Acute eczema refers to a rapidly evolving red rash, which may be blistered and swollen. Chronic dermatitis refers to a longstanding irritable area. It is often darker than the surrounding skin, thickened and much scratched. Dermatitis affects about one in every five people at some time in their lives. It results from a variety of different causes and has various patterns.

Dermatofibroma

A dermatofibroma is a common benign fibrous skin lesion. A dermatofibroma is also sometimes called a histiocytoma. The cause is unknown but some believe it arises at the site of a minor injury, especially an insect bite or thorn prick. Dermatofibromas most often occur on the legs and arms. Once developed, they usually persist for years. They appear as firm-feeling nodules, often yellow-brown in color, sometimes quite dark, especially in dark colored skin. If the skin over a dermatofibroma is squeezed a dimple forms, indicating tethering of the skin to the underlying fibrous tissue. A dermatofibroma is of cosmetic significance only and seldom causes any symptoms.

Dermatophytosis

(see fungal infection)

Drug Eruption (rash)

These rashes can mimic virtually all of the many rashes that exist in Dermatology, and must be considered first on the differential diagnosis in the apperance of a sudden symmetrucal eruption. Drug eruptions are caused by both immunologic and nonimmunologic mechanisims and are provoked by the oral or topical administration of a drug.

Dry Skin

(see Xerosis)