Down syndrome, alopecia universalis, and trachyonychia.

A 16-year-old boy with Down syndrome and alopecia universalis had dystrophy of all nails. A presumptive diagnosis of tinea unguium, common in persons with Down syndrome, had been made nine years earlier. Despite antifungal therapy, the condition of the nails worsened. We were unable to detect fungi, and believe that his nail changes are most consistent with alopecia-associated trachyonychia (formerly 20-nail dystrophy), a condition not previously reported in persons with Down syndrome.