History and physical examination are adequate for diagnosing many skin lesions. Some require biopsy or other testing.

Important information to obtain from history includes

• Personal or family history of atopy (suggesting atopic dermatitis)
• Occupational exposures (contact dermatitis)
• Long-term exposure to sunlight or other forms of radiation (benign and malignant skin tumors)
• Systemic disease (diabetes and Candida or tinea, hepatitis C, and cryoglobulinemia)
• Sexual history (syphilis and gonorrhea)
• Use of drugs (Stevens-Johnson syndrome, toxic epidermal necrolysis)
• Travel history (Lyme disease, skin infections)

A negative history is as important as a positive history. The history of the particular skin lesions is also important, including time and site of initial appearance, spread, change in appearance, and triggering factors.

Visual inspection is the central evaluation tool; many skin disorders are diagnosed by the characteristic appearance or morphology of the lesions.

Last full review/revision March 2013 by Robert J. MacNeal, MD