Test your diagnostic skills in our regular dermatology quiz. What is the cause of these scaly annular lesions?
A 10-year-old girl presents with a four-month history of a scaly annular eruption that has been gradually evolving on her trunk (Figure 1). It is mildly itchy, but not severely enough to wake her at night.
Tinea was initially suspected, but skin scrapings for fungal infection have returned negative results. The patient has not had any recent contact with pets or other animals, and treatment with antifungal creams has been ineffective.