A 15-year-old girl is brought in by her mother for evaluation of a rash that developed following a “candling” treatment she underwent two weeks ago at a beauty spa.
The treatment, which was performed to eliminate scaling in her external ear canal, involved dripping hot wax from a burning candle into the external auditory meatus. The cooled wax was peeled away, along with the attached scaling. A new, asymptomatic, scaly rash has since appeared in the same area—far worse than the original.
There is no history of recent infection or joint pain, or family history of skin disease.
Heavy, uniform, white scaling on a salmon-colored base covers the external auditory meatus, extending 3 or 4 mm into the concha. Similar, milder changes are observed in the left ear.
There are scattered pits in three fingernails, white scaling in the scalp above and behind both ears, and faint pink scaly patches on both knees and elbows.
What is the diagnosis?