Trachyonychia associated with alopecia areata: a clinical and pathologic study.

Forty of 1095 patients (3.65%) with alopecia areata had severe nail changes that fulfilled the clinical criteria for the diagnosis of trachyonychia. Twelve of these patients had a nail biopsy. A mild to moderately dense lymphocytic infiltrate associated with exocytosis and spongiosis was detected in the proximal nailfold, nail matrix, nail bed, and hyponychium of 11 patients. One patient showed the pathologic changes of lichen planus; lichen planus of the skin developed 6 months after the nail biopsy. Immunohistochemical characterization on paraffin-embedded sections showed that the inflammatory infiltrate consisted of peripheral T lymphocytes. Immunophenotyping on frozen sections was performed in four cases. The results revealed a T4/T8 ratio of 2:1 and the presence of Langerhans cells in the nail matrix. Our results show that trachyonychia is an uncommon nail manifestation of alopecia areata. Distinctive pathologic features of mild to moderately dense lymphocytic infiltrate associated with exocytosis and spongiosis characterize trachyonychia as well as the other nail abnormalities caused by alopecia areata. The clinical association of trachyonychia with alopecia areata does not exclude that the nail abnormality can be due to other diseases such as lichen planus.