Pyoderma gangrenosum.

Pyoderma gangrenosum (PG) is an idiopathic, ulcerative, noninfective chronic inflammatory skin disorder of unknown etiology. It is associated with systemic medical illness in 50% of cases like inflammatory bowel disease, systemic arthritis, haematological diseases and malignancies. Characteristic lesions begin as pustule or vesiculopustule and progresses to an ulcer or deep erosion with violaceous overhanging or undermined borders. Diagnosis of pyoderma gangrenosum is clinical and depends on exclusion of other causes of cutaneous ulceration. The management of PG is treatment of underlying systemic medical illness and judicious use of immunosuppressants. Association of PG with these medical illnesses and treatment with immunosuppressants make the clinical utility for internists, gastroenterologists, haematologists and rheumatologists.