Pityriasis rubra pilaris–like eruption in the setting of transient acantholytic dermatosis

Transient acantholytic dermatosis (TAD; also known as Grover disease) often presents as pruritic erythematous papules on the chest or back, most frequently seen in older men. Histopathology is significant for acantholysis and dyskeratosis.1 Pityriasis rubra pilaris (PRP) is a rare condition that classically presents with keratotic papules and perifollicular erythema that coalesce to form generalized erythroderma with islands of uninvolved skin.2 Although alternating vertical and horizontal orthokeratosis and parakeratosis with follicular plugging are the most frequently described histopathologic findings in PRP, both focal and extensive acantholysis have also been increasingly described in this condition, leading to the notion of a potential overlap between TAD and PRP.