ECCRINE SWEATING IN PSORIASIS

SUMMARY.— The lesions of psoriasis produce very much less sweat on pharmacological stimulation than clincally unaffected adjacent skin. The Na+ K+ concentrations of this sweat are very much decreased. The sweat rate increased after the lesions were stripped, sweat Na+ and K+ increased, but to a lesser extent. It is concluded that there are two abnormalities of sweat gland function in the plaques of psoriasis: (i) superficial obstruction of the ducts leading to hypohidrosis, (ii) an abnormality of absorption by the duct leading to inappropriately low sweat electrolyte concentration. The absence of miliaria despite duct blockage is discussed in relationship to the hypothesis that miliaria is due to an imbalance between the capacity of the coil to secrete and the ability of the duct to absorb.