This document discusses the approach to dermatologic diagnosis. There are two main clinical situations - incidental findings like asymptomatic lesions that are medically inconsequential, and important lesions that should not be overlooked like melanomas. The other situation is the chief complaint of the patient, which can be minor problems like localized rashes or more serious skin signs in sick patients. It then lists examples of serious skin signs in sick patients such as generalized rashes with fever, blisters, pustules or scaling that could indicate conditions such as viral exanthems, pustular psoriasis, or exfoliative erythroderma.