The lesions on this 41-year-old African-American woman’s skin have waxed and waned over the years—but they’re always on her mind. They are most prominent on her arms and trunk but crop up almost anywhere on her body.
When they manifest—for no apparent reason—they itch, creating an irresistible urge for the patient to pick at them. This provides some relief, both from the itching and from her feeling that there is “something in there” that she needs to remove. Fairly often, her digging (with fingernails) results in “finding” white bumps at the ends of tiny hairs.
As these small excoriations heal, the wounds itch—compelling her to pick the site open again. She knows she is caught in a vicious cycle but doesn’t know how to stop. Selective serotonin reuptake inhibitors have been tried, with little to no effect.
The patient’s type IV skin is covered with dark brown, maculopapular lesions that are so numerous and large (average diameter, 2 to 3 cm) that they are impossible to ignore. Her palms, soles, face, and midback are spared.
Only a few of the newer lesions are palpable, showing faint signs of central excoriation. Previous biopsies failed to show significant pathology.
The patient appears ill at ease during history-taking. She admits to picking her skin for many years but doesn’t believe she is inhabited by any kind of bug. The skin on her wrists and between her fingers is clear. Her 3-year-old daughter’s skin is free of notable changes.
What is the diagnosis?