Stains and smears: resident guide to bedside diagnostic testing.

Dermatology residents often are on the front line when it comes to treating patients with complicated skin disorders, frequently seeing these cases first before discussing their findings and plan with an attending physician. Bedside testing modalities can help facilitate arriving at a diagnosis quickly, allowing for rapid initiation of treatment. The potassium hydroxide (KOH) preparation, Tzanck smear, mineral oil preparation, and Gram stain are easy to perform quickly and provide valuable diagnostic information. The purpose of this article is to consolidate these frequently used tests into a useful reference for the training and practicing dermatologist.