Pyoderma gangrenosum: a report of 44 cases with follow-up.

Results of a study of 44 patients with pyoderma gangrenosum (PG) are presented. Each patient was diagnosed using standardized diagnostic criteria and followed up systematically. Thirty patients were women and 14 men. Their mean age was 50 years (range 11-80). Twenty patients had idiopathic and 14 parainflammatory occurrences (e.g. ulcerative colitis, Crohn's disease), whereas in 10 patients an associated haemoproliferative disease or neoplasia was noted. Whereas idiopathic and parainflammatory PG was found predominantly in women, the association with haemoproliferative diseases occurred more often in men. The lower legs and feet represented the typical predilection sites. Fifty-two per cent of patients had one lesion, 37% had up to five, and 11% had more than five lesions. Histologically, lymphocytic and/or leucocytoclastic vasculitis was present in 73% of the biopsy specimens obtained from the borders of the lesions. Long-term follow-up (n = 42, median follow-up 26.5 months) revealed that eight patients had died, in six cases due to the PG and/or the underlying diseases. Of the remaining 34 patients, 44% are in complete remission without further treatment, whereas continuing therapy is needed in 56%. No difference between idiopathic and parainflammatory PG was demonstrable in the follow-up and in no patient with idiopathic PG was a possibly related disease diagnosed in the follow-up. These data suggest that PG should be considered to be an independent disease and not a purely cutaneous complication in most patients.