An Unusual Trigger of Grover's Disease (GD).

Grover's disease (GD) is a rare skin condition that presents as a pruritic, erythematous papular, or papulovesicular rash. We report a unique case of GD triggered by honeybee stings. An 80-year-old Caucasian male presented with a pruritic papulovesicular rash on his trunk and arms after being stung by honeybees. He had a history of honeybee venom allergy and developed immediate erythema at the sting sites, which progressed over two days. His laboratory tests were unremarkable, including a complete blood count and comprehensive metabolic profile. Despite using oral antihistamines, emollients, and topical steroids, his rash continued to progress onto his neck, face, scalp, and back. A skin biopsy of the rash revealed suprabasilar and intraspinous acantholysis with focal corps ronds and upper dermis lymphocytic infiltrate -- the histopathologic finding of GD. He had failed first-line treatment for GD. However, after five months and significant morbidity, he was successfully treated with systemic steroids, high-potency topical steroids, emollients, and antihistamines for extensive and prolonged GD. This case report highlights honeybee venom as a possible trigger of GD and discusses a potential immune-mediated etiopathogenesis, which can be used to guide further research and management of this rare disease.