PYODERMA GANGRENOSUM
Pyoderma gangrenosum is a skin disorder that usually affects the lower extremities and is associated with many disease states. Clinically, lesions often start as pustules or nodules that eventually breakdown and extend into the surrounding tissue with a leading edge that has a rolled border appearance.There are four main variants to include ulcerative, pustular, bullous, and vegetative. The most common form is ulcerative pyoderma gangrenosum. The diagnosis is made clinically and confirmed by biopsy.
Early-stage lesions may respond to local therapy with topical sodium cromoglycate or intralesional steroid injections.(triamcinolone hexacetonide 10-40 mg/dL). Also, local therapy entails keeping the lesions clean and moist with normal saline compresses covered with moisture-retentive dressings. Another form of local therapy includes intralesional injections of cyclosporine A (1:3 dilution with isotonic saline) given twice weekly for a cumulative dose of 35 mg. Other forms of therapy for early lesions includes benzoyl peroxide, tacrolimus, 5-aminosalicylic acid, granulocyte macrophage colony-stimulating factor, split skin grafting, cultured keratinocyte auto and allografting, and hyperbaric oxygen therapy.
More advanced lesions require systemic therapy. Systemic steroids either 1-3 mg/kg/day of prednisone or methylprednisolone pulse therapy (1 gm IV for 1-5 days) are considered first line therapy. Once lesions respond to treatment, the dose may be slowly tapered as rapid withdrawal may result in disease recurrence. Another effective agent which may be used instead of steroids is cyclosporin A (5-10 mg/kg/day). Second line agents which are effective include dapsone (100-200 mg/day), clofazimine (200-400 mg/day for 4 weeks), rifampicin, vancomycin, mezlocillin, tetracyclines (especially minocycline), chlorambucil (2-4 mg/day), cyclophosphamide (150 mg/day), and tacrolimus (0.15 mg/kg BID). Other potential therapies include plasmapheresis followed by intravenous cyclophosphamide therapy, alpha 2a-interferon, intravenous immunoglobulins, colchicine, and mycophenolate mofetil.