Background: Pyoderma gangrenosum (PG) may fail to respond to corticosteroids. Immunosuppressive and cytotoxic agents are useful in patients with recalcitrant disease. We describe our experiences with chlorambucil for PG.

Objective: Our purpose was to evaluate the effectiveness of oral chlorambucil in patients with PG recalcitrant to treatment with prednisone, immunosuppressive therapy, or both.

Methods: Six patients with recalcitrant PG were given oral chlorambucil 2 to 4 mg/day. Four patients were treated with a combination of prednisone and chlorambucil, and two received chlorambucil alone. Response was based on (1) a diminution in the size of the ulcers, or their complete healing, or (2) a decrease in the dose of corticosteroid therapy.

Results: Beneficial effects were noted within 6 to 8 weeks in all six patients, and corticosteroids were eventually discontinued in all patients. Currently only two patients are still receiving chlorambucil; the other four stopped chlorambucil after 6 to 24 months of treatment. Their disease has remained in remission for 4 to 9 years. Relapse of disease occurred within 1 to 4 months after stopping therapy in one of the two remaining patients or reducing the dose in the other. In both patients, the disease is again responding to treatment. Minimal chlorambucil toxicity has been noted, consisting of leukopenia in one patient.

Conclusion: Our findings suggest that chlorambucil is an effective corticosteroid-sparing agent for the control of PG.