Recalcitrant pustular eruptions of the extremities.

Forty-seven biopsies of pustules from patients with recalcitrant pustular eruptions of the palms and soles were examined blind and the results were subsequently compared among three clinical sub-groups: acrodermatitis continua, pustular psoriasis and pustulosis palmaris et plantaris. With the exception of three cases, it was not possible to make a diagnosis of psoriasis on the basis of histology alone. Histological findings were otherwise uniform and typical: intra-epidermal, unilocular, well-delineated pustules. No significant differences were found among the three subgroups. In view of the uniform histology, the unknown etiology and the uncertain clinical classification, the authors prefer the clearly descriptive term pustulosis palmaris et plantaris.