A 29-year-old woman and her 40-year-old husband present together for evaluation of similar problems: One month ago, they both experienced sudden hair loss—the wife in two spots on her scalp, the husband in his beard. In both cases, the hair came out suddenly, without any symptoms. Neither has had this problem before. Both patients are otherwise healthy, but they admit to being under a great deal of stress in the weeks prior to onset of the condition.
Before consulting dermatology, they were seen in an urgent care clinic, where they were diagnosed with “ringworm.” Twice-daily application of nystatin cream was prescribed—to no good effect.
EXAMINATION
On each side of the woman’s parietal scalp is a round, completely hairless patch with exceptionally well-defined margins. The sites are otherwise unremarkable, free of redness, edema, or scaling. Each lesion measures about 3.5 cm in diameter. No lymph nodes are palpable in the adjacent neck.
On the man’s left jawline is a solitary, round, 4-cm, hairless patch. It is also free of edema, erythema, or epidermal disturbance of any kind. There are no palpable lymph nodes in the drainage area.
What is the diagnosis?