Grover's disease: dermoscopy, reflectance confocal microscopy and histopathological correlation.

Grover's disease is a benign condition of unknown origin characterized clinically by an erythematous papulovesicular eruption and histopathologically by intraepidermal clefting and four different patterns of acantholysis: Darier-like, pemphigus-like, spongiotic, and Hailey-Hailey-like. A case of a 54-year-old female affected by Grover's disease and showing a Darier-like histopathological pattern is described. Polarized light dermoscopy (PLD) revealed the presence of polygonal, star-like shaped yellowish/brownish areas of various sizes surrounded by a thin whitish halo. Handheld reflectance confocal microscopy (RCM) showed the presence of intraepidermal dark spaces histopathologically corresponding to intraepidermal clefts, roundish, bright cells correlating to acantholytic keratinocytes, target-like cells with a dark center and a highly reflectant halo corresponding to dyskeratotic cells, and epidermal, polygonal, structureless areas reflecting hyperparakeratosis. In conclusion, the use of PLD and RCM combined with clinical presentation, personal/family history, and genetic evaluation may be useful for the non-invasive diagnosis of Darier-like Grover's disease.