Ecthyma gangrenosum without bacteraemia in a leukaemic patient

Abstract

Ecthyma gangrenosum is a well recognized cutaneous manifestation of Pseudomonas aeruginosa infections in immunocompromised patients. Most cases of ecthyma gangrenosum have been associated with concomitant septicaemia. However, ecthyma gangrenosum rarely develops due to Ps. aeruginosa in the absence of bacteraemia. We report a rare case of a nonsepticaemic form of ecthyma gangrenosum presenting as a large solitary necrotic ulcer in a patient with acute myelogenous leukaemia. A culture from the lesion revealed the presence of Ps. aeruginosa, but the results of repeated blood cultures were negative. Histological examination revealed numerous tiny eosinophilic bacilli in the dermis and panniculus with Gram's stain.

Ecthyma Gangrenosum: A Rare Cutaneous Manifestation Caused byStenotrophomonas maltophiliain a Leukemic Patient

“…The skin lesions of ecthyma gangrenosum are the manifes-tation of a necrotizing vasculitis 3 . The lesion characteristically begins as an erythematous nodule, macule, vesicle, or bullae and evolves into gangrenous ulcerations with black eschar and a surrounding rim of erythema 6,11,12 . The vesicles, initially filled with serous fluid, appear on the surface of the edematous skin, and then coalesce to form large bullae.…”

“…The pathogenic mechanism of EG is unknown, but several possible mechanisms have been suggested 6 . Two mechanism of EG have been well described.…”

“…Two mechanism of EG have been well described. In classic bacteremic EG, the skin lesions are considered to represent blood-borne metastatic seeding of an organism into the skin 5,6,14 . Our patient also revealed a positive blood culture result.…”

“…Our patient also revealed a positive blood culture result. In nonbacteremic EG, the lesion is located at the site of entry or inoculation of the organism into the skin 5,6 . Some investigators have suggested that nonbacteremic EG may be an early type of EG 6 .…”

“…The lesions are present in the gluteal and perineal regions or on the extremities, but they can occur anywhere on the body 1,3,4 . Most cases of ecthyma gangrenosum are associated with Pseudomonas aeruginosa bacteremia 5,6 . But numerous other organisms have been reported to cause EG.…”