Psoriasis-like lesions in guinea pigs receiving propranolol.

Background: beta-Blockers cause a psoriasiform eruption. We investigated the skin effects of systemic propranolol in a formal protocol.
Methods: Propranolol, 0.1 mg/day, was used systemically by gavage in eight albino guinea pigs. Normal saline was given to another group of seven guinea pigs.
Results: Propranolol produced psoriasiform lesions in five of seven guinea pigs on the 30th day. Biopsies showed acanthosis, parakeratosis, microabscesses, and cellular infiltration of upper dermis. Topical application of propranolol did not produce clinical psoriasiform changes, while acanthosis and papillomatosis was observed in six of the six guinea pigs.