Diagnostic procedures of the skin. Part two: Skin biopsy and other tests.

The diagnosis of skin lesions involves the same principles and approaches required for other clinical problems. "Shotgun" therapy based on visual recognition alone is not an adequate clinical approach. A pertinent history and careful physical examination, supplemented by carefully selected diagnostic procedures, is usually necessary for skin diseases. The indications, limitations, interpretation, and techniques of diagnostic procedures must be well understood to obtain reliable and useful information. The selection of the specific method of skin biopsy, for example, may be based on cosmetic considerations, location and nature of the lesion, and the physician's understanding of the biology and histopathology of the suspected diagnosis. This is the second paper in a two-part series dealing with diagnostic procedures of the skin. Various kinds of skin biopsy, touch imprints, the Tzanck smear, and immunofluorescent studies are described as they relate to the everyday practice of the family physician.