STD interactive case challenge--diagnosing and treating chronic vulvar pain and erythema

A 36-year-old Caucasian woman arrives in your office, her chief complaint being vulvar pain and discomfort of 2 years' duration. She says that the onset of vulvar erythema and pain was gradual, beginning with mild tingling discomfort and eventually developing into dyspareunia and pain whenever she attempted to insert tampons, wore tight-fitting pants, or went horseback riding. The patient denies having vaginal discharge, change in menstrual pattern, or dysuria. She says she complained of the problem to several previous clinicians, who recommended anti-infective treatment for candidal vulvovaginitis, bacterial vaginosis, and recurrent cystitis, yet the symptoms persisted. One physician suggested a psychiatric evaluation, but the patient refused. She switched soap, shampoo, and even underwear fabric in an unsuccessful effort to ameliorate the symptoms. Over the past 6 months she has become increasingly frustrated with this problem.