Sorting out common causes of abnormal vaginal discharge.

A chief complaint of abnormal vaginal discharge requires a broad differential diagnosis of both infectious and noninfectious causes. The patient's history and the physical exam should guide the choice of laboratory studies, and a complete physical exam that includes a thorough examination of both the external and internal genitalia will yield additional important information. Empirical treatment is unacceptable, considering the low cost of pH testing and saline and KOH preps compared to the cost of inappropriate treatment, repeat office visits, and the likelihood that eventually these tests will need to be performed. Some of the infectious causes of abnormal discharge may lead to serious complications with inappropriate treatment.