Superficial granulomatous pyoderma is a rare disease that is considered to be a variant of PG. The pathogenesis of SGP remains unknown; however, pathergy is believed to be the precipitating factor in most cases but not all. It has been suggested that SGP may be a localized delayed-type hypersensitivity reaction of the skin to a yet unidentified endogenous or exogenous organism or antigen.[1,2,9]
Superficial granulomatous pyoderma shares some similarities and is often mistaken for classic PG, but there are distinctive characteristics in the location, histologic features, prognosis, and treatment that are unique to SGP (Table 1). Clinically, the site of predilection for SGP lesions is the trunk. Superficial granulomatous pyoderma rarely affects the face. Unlike PG, SGP is not associated with serious underlying systemic, autoimmune, or other diseases. Superficial granulomatous pyoderma lesions tend to appear as a single, nontender, well-defined superficial ulcer with exophytic or vegetating clean granulations. Histopathologically, the ulcers show a characteristic 3-layered granuloma: an innermost zone of necrotic debris and neutrophils, a surrounding layer of granulomatous inflammation with histiocytes and giant cells, and an outer layer composed of plasma cells and eosinophils. The major differential diagnosis for SGP is classic PG. Other differentials include mycobacterial and fungal infections, foreign-body granuloma, vasculitis, halogenoderma, and other granulomatous diseases.
Effective treatment of SGP differs somewhat from PG. Systemic corticosteroids are first line in the treatment of PG but are usually not necessary to control SGP lesions. Superficial granulomatous pyoderma is generally responsive to conservative treatment with antibacterial or local anti-inflammatory agents. There are, however, some exceptions that require more aggressive therapies. Interestingly, in many of these intractable cases, SGP involved the face.[2,3,5,7] It has been suggested that facial involvement with SGP may be more refractory to conservative treatments. These cases of SGP with facial involvement have been successfully treated with cyclosporine, intravenous immunoglobulin therapy, a combination of dapsone and oral corticosteroids, and more recently, infliximab. In all of these studies, conservative therapy was attempted but ultimately failed.
Pyoderma gangrenosum is believed to exist as a clinical spectrum with classic PG representing the more acute and debilitating end, while SGP represents a more indolent and benign opposite end. This concept may help explain why certain cases of SGP do not respond well to conservative treatment in that they may be exhibiting features that are more consistent with classic PG, in which case, milder therapies would be ineffective.
Superficial granulomatous pyoderma is a slowly progressive, relatively benign disease that generally has a favorable prognosis with conservative treatment and does not require systemic immunosuppressive agents. Facial involvement with SGP, however, may represent a more aggressive clinical entity that is distinct from typical SGP in nature and may require more intensive management at the onset. Delay in initiating appropriate treatment, combined with excessive trauma from multiple reexcisions, may result in poor cosmetic and functional outcomes in patients with SGP, especially for lesions involving the face.
For patient J.M. presented in this case of SGP, the appearance of the final scar is clearly suboptimal; however, it was judged that the risk of further pathergy was great with continued surgical management of this wound, so no attempt at scar revision was contemplated and appropriate medical management was initiated. We present this case to make plastic surgeons aware of a medical condition that may make plastic surgical intervention unpredictable and potentially more damaging. It is important for plastic surgeons to recognize the clinical and histopathologic presentation of SGP to avoid disease progression and permanent disfigurement.
ePlasty. 2012;12 © 2012 Open Science Company