August 1st 2006
The parents of a 3-year-old girl sought evaluation of their daughter's hair loss. During the past several months, a large patch of alopecia with scaling had developed. The differential diagnosis included seborrhea, trichotillomania, and tinea capitis. Joe R. Monroe, PA-C, MPAS, of Tulsa, Okla, writes that in seborrhea, scaling typically occurs throughout the scalp without the patches of alopecia seen in this patient. Broken-off hairs--a key to trichotillomania--were absent here. A potassium hydroxide preparation of scrapings that contained hairs from the affected area were positive for the "endothrix" phenomenon--the finding of fungal elements inside the hair shaft. Palpable, tender suboccipital lymph nodes were also detected. Both of these findings are common in tinea capitis and essentially confirm the diagnosis.