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Dermatology is a specialty in which visual inspection allows for rapid diagnosis. A brief physical examination prior to a lengthy history is valuable because some of the classic skin diseases with obvious morphologies allow a “doorway diagnosis” to be established. The tools the physician needs are readily available: magnifying glass, glass slide (for diascopy to determine if a lesion is blanchable), adequate lighting, a flashlight, alcohol pad to remove scale or makeup, scalpel, and at times a Wood lamp. Universal precautions should always be used.
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The ability to describe lesions accurately is an important skill, as is the ability to recognize specific patterns. These abilities aid clinicians in their approach to the patient with a cutaneous eruption both in developing a differential diagnosis and while communicating with other physicians. The classic dermatologic lesions are defined in Table 17–1.
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The skin shields the internal organs from harmful xenobiotics in the environment and maintains internal organ integrity. The adult skin covers an average surface area of 2 m2. Despite its outwardly simple structure and function, the skin is extraordinarily complex. The skin is affected by xenobiotic exposures that occur through many routes. Dermal exposures themselves are important as they account for approximately 7% of all human exposures reported to the American Association of Poison Control Centers (Chap. 130). The clinician must obtain essential information as to the dose, timing, route, and location of exposure. Knowledge of the physical and chemical properties ...