SUMMARY.— A series of 104 cases of generalized pustular psoriasis has been studied. The syndrome occurs predominantly in the second half of life, affecting both sexes. Two quite distinct sub-groups were discernible. In the first the pre-pustular phase of psoriasis began early in life, was typical through-out and was prolonged. At least one third of these cases were apparently precipitated by the withdrawal of systemic corticosteroid therapy. Others were provoked by pregnancy or infection. It is likely that this type is usually extraneously provoked. In the second, the psoriasis was of late onset and atypical, acral or flexural patterns predominating in the pre-pustular phase. In these progress to generalized pustular disease was rapid and apparently spontaneous.
Four clinical patterns of generalized pustular phase were apparent and have been named the Zumbusch, annular, localized and exanthematic types. The Zumbusch type was characterized by widespread fiery erythema, sheeted pustulation and scarlatiniform peeling, accompanied by malaise, fever and often leucocytosis. The annular type was a more low-grade sub-acute affection characterized by gyrate and annular pustular lesions and little systemic disturbance. The exanthematic type arose de novo, usually as a single short-lived episode following infection or drug exposure. In the localized type restricted areas of pustular psoriasis developed in and around ordinary psoriatic plaques.
Two thirds were erythrodermic at some stage and one third had polyarthritis. Oral lesions occurred in 5 and hypocalcaemia in 5 during pustular phases.
The different clinical patterns of pustular psoriasis have been interpreted in terms of the balance between vascular hypertrophy, epidermopoiesis and leucocytic immigration into the epidermis.