Primary eruption of prurigo simplex subacuta.

28 patients with typical picture of prurigo simplex subacuta were examined for the primary eruption. In all patients, the first visible lesion was a papule, at the top of which a vesicular element was never seen. 46 biopsy specimens of the initial eruption were serially sectioned. The histological changes were found in connection with hair follicles, which consisted of spongiosis and mononuclear cell migration at the follicular epidermis and perifollicular infiltrates of mononuclear cells.