Fibroelastolytic papulosis with vacuolar interface dermatitis: A new observation

Abstract

dystrophy (right nail) and habit-tic deformity (left nail) was made. These were attributed to repetitive cuticle manipulation from pruritus secondary to atopic dermatitis. Median canaliform nail dystrophy presents as a midline longitudinal groove with multiple transverse parallel lines, resulting in a fir tree appearance. In contrast, habit-tic deformity is characterised by multiple transverse ridges and lack of longitudinal splitting seen in median canaliform nail dystrophy. Habit-tic deformity is frequently observed in the setting of repeated manipulation of the proximal nail fold, while the mechanism behind median canaliform nail dystrophy is not fully understood; however, presumably it arises from a temporary defect due to localised dyskeratosis in the nail matrix. An association between median canaliform nail dystrophy and macrolunulae supports the role of trauma in the pathogenesis of median canaliform nail dystrophy; more nail matrix lies outside of the proximal nail fold and thus is more susceptible to damage. Median canaliform nail dystrophy has also been associated with the use of systemic retinoids and familial occurrence. Coexistence of both conditions suggests the two have a similar pathogenesis and may be on the same disease spectrum. Manipulation of the cuticle in the setting of pruritus was the underlying precipitant in our case. Findings of macrolunulae, absence of cuticle and chronic paronychia correlated with this. Given our case and a previously published case both demonstrated median canaliform nail dystrophy and habit-tic deformity affecting the right and left thumbnail, respectively, it is possible that hand dominance may be a factor in the pathogenesis and coexistence of both conditions.