Pathologic Quiz Case: Unexplained Hair Loss—1 Boy, 2 Cats, and 1 Dog

In 2003, a study investigated a 7-year-old boy and his pets (two cats and a dog) who all experienced focal hair loss. The study concluded that the boy had trichotillomania, a disorder characterized by recurrent hair pulling, leading to noticeable hair loss. This diagnosis was confirmed through a scalp biopsy, which revealed pigment casts with keratinous debris in the follicles, distorted hair shafts, and an increased number of catagen hairs. The study also indicated that trichotillomania in children typically represents a habit, with psychotherapy aimed at habit reversal and the establishment of a support network being the primary treatments.