Nail changes in alopecia areata: an update and review.
Nail changes are a common feature of alopecia areata (AA) and are a significant source of cosmetic disfigurement and functional impairment. This review provides an update of the prevalence, clinical and histopathological features, pathogenesis, differential diagnosis, clinical course, prognosis, and management of nail changes in patients with AA. Searches for peer-reviewed journal articles were conducted using the PubMed/MEDLINE database with the search terms "nail changes alopecia areata," "alopecia areata nails," and specific searches on "trachyonychia alopecia areata" and "pitting alopecia areata." Other sources of articles included the reference lists of retrieved articles. Nail changes are a common feature of AA, with an average prevalence of 30%, and can cause significant disfigurement and loss of function. Pitting and trachyonychia were by far the most common manifestations of AA, with an average prevalence of 20 and 8%, respectively. Red spotted lunulae, onycholysis, and punctate leukonychia were other reported findings. Other etiologies, such as onychomycosis or lichen planus, may coexist with or confound the diagnosis. There is limited published data on the clinical manifestations of AA-associated nail changes and therapeutic options. Larger controlled trials are necessary to guide treatment decisions.