Psoriasis palmaris and psoriasis plantaris

Psoriasis palmaris and psoriasis plantatvt are important local varieties. These local varieties are infinitely rare. Of course, instances of so-called psoriasis palmaris and plantaris are common enough, but they are practically always syphilitic. Non-syphilitic psoriasis may occur, though rarely, in connection with general psoriasis. But when such a condition exists as the sole disease, it is syphilitic and nothing else, and the concomitance of sore tongue and other evidences of constitutional syphilis at once make the diagnosis certain. The skin in the affected parts is generally thick, and dry, harsh, discolored; the scaliness is not very marked, but the superficial layers peel off from time to time. Presently the surface cracks and fissures, and healing is very tardy; occasionally the surface bleeds. The muscular movements of the hand may be painful.