Chronic-Recurrent, Limb-Predominant Grover Disease in a Young Adult: A Clinicopathological Diagnostic Challenge.

Grover disease (GD), or transient acantholytic dermatosis, is an acquired acantholytic dermatosis that classically affects the trunk of older men, although persistent, recurrent and atypically distributed forms are increasingly recognised. We report a 29-year-old man with chronic-recurrent, intensely pruritic GD, with an estimated onset approximately six months before his first documented dermatologic assessment. The eruption predominantly involved the upper and lower limbs, with limited truncal involvement. Because of the atypical age and distribution, and because acantholysis was focal and minimal in individual specimens, the diagnosis rested on clinicopathological correlation across serial biopsies obtained during separate disease episodes, which showed spongiotic and acanthotic changes, focal parakeratosis, lichenoid and perivascular inflammation, and focal acantholysis with dyskeratosis. Direct immunofluorescence, performed during topical corticosteroid treatment, was nonspecific and did not support an autoimmune blistering disorder, although this result must be interpreted with caution. Laboratory investigations were unremarkable apart from a moderately elevated total serum immunoglobulin E (IgE) (223.2 IU/mL), a nonspecific finding that does not establish a type 2 immune phenotype in this patient. A combined regimen of acitretin, an oral antihistamine, a topical corticosteroid and barrier-directed care was temporally associated with marked improvement, the Dermatology Life Quality Index falling from 17/30 to 5/30 over three months. We briefly review the histopathological patterns, differential diagnosis and management of GD and its emerging molecular and immunological context. This case illustrates the breadth of the clinical spectrum of GD, the diagnostic pitfalls of focal acantholysis and of immunofluorescence performed under treatment, and the need to consider GD in young patients with chronic-recurrent, predominantly extra-truncal eruptions.