Answer:
Multiple skin abscesses with necrosis and undermining ulcerations occur in the necrotizing lesion of the skin called pyoderma gangrenosum. It is often associated with ulcerative colitis (50% of patients). It has also been reported to occur in association with other gastrointestinal disorders (diverticulosis, regional enteritis, peptic ulcer disease, hepatitis, and carcinoid tumor) as well as rheumatoid arthritis, pulmonary diseases, and hematologic disorders. No systemic disease is evident in 20% of the patients with pyoderma gangrenosum. No specific organism or combination of organisms has been identified with this disease entity, although frequently Proteus and other gram-negative organisms and beta-hemolytic streptococci have been cultured from these wounds. Systemic and topical antibiotic therapy have been of some use in controlling the active disease process. It appears today that the basic lesion is not a primary infection but may be a necrotizing cutaneous vasculitis with rapidly developing hemorrhagic liquefying tissue necrosis of the skin. It is characterized by ulceration surrounded by bluish hemorrhagic cribriform edges. The course is protracted and in some instances fulminant.
Careful control of pathogenic bacteria with culture and sensitivity tests preceding antibiotic therapy, associated with conservative debridement of the necrotic tissues, has been successful in many instances. It appears important to debride only the grossly necrotic tissue and not to incise the adjacent intact tissues, thereby avoiding extension of the disease beyond the operative debridement. Local and systemic steroid therapy immunosuppressives (e.g., azathioprine) and systemic sulfones have been helpful. Caution must be exercised when treating these patients with local injections because of the possibility of local skin trauma, which may induce new pyoderma gangrenosum lesions.