Trachyonychia: a retrospective study of 122 patients in a period of 30 years.

Background: Trachyonychia is a nail disease characterized by longitudinal striations, ridges, fissures and/or pitting. This condition can be both idiopathic and associated with other dermatologic diseases. Objective and methods: The aim of this retrospective study was to analyse the clinical features, onychoscopy, therapy efficacy and outcome of 122 patients with trachyonychia visited at the Hair Disease Outpatient Consultations of the Dermatology Unit of the Department of Experimental, Diagnostic and Specialty Medicine of the University of Bologna, from 1988 to 2018. Results: Opaque trachyonychia was the most observed type while shiny trachyonychia, less common, was present especially in milder cases. Pitting was the most frequently observed feature (80.3%), followed by koilonychia (45%) and hyperkeratosis (19.6%). Nail matrix longitudinal biopsy was performed for diagnosis confirmation in 29 cases, and spongiotic was the most common pattern. Topical therapy was prescribed in 109 patients while systemic treatments were reserved for severe cases (38 patients); 22 patients did not receive any treatment. A marked improvement in the appearance of the nails or even a total resolution was seen in 63 patients. Conclusions: Trachyonychia can occur at any age but is more frequent in children and often associated with alopecia areata. The pathological diagnosis of trachyonychia is not mandatory as the disease has generally a benign outcome. Considering the absence of pain and the high rate of spontaneous resolution, treatment is often prescribed only for cosmetic reasons or reserved for severe cases.