Ecthyma Gangrenosum and Panniculitis Secondary to Acute Pseudomonas Myositis Without Bacteremia.

Abstract

Ecthyma gangrenosum (EG) is a relatively uncommon cutaneous manifestation of an underlying Pseudomonas aeruginosa infection and is clinically described as necrotic with gangrenous ulcers surrounded by erythematous halos. Cases of EG may occur in the absence of bacteremia and have been increasingly reported in literature. Here we present a patient with features of both EG and panniculitis, despite the lack of underlying bacteremia. A 57-year-old male presented to the emergency department with unrelenting right-sided lower back pain and an "itchy and painful" rash of four to five day duration. The patient had an extensive history of intravenous drug abuse and had been hospitalized multiple times for Pseudomonas bacteremia. Upon examination, there were diffuse, erythematous subcutaneous nodules and several individual necrotic ulcerations on the abdomen, upper and lower extremities, surrounded by erythematous halos. An MRI revealed myositis and edema in the right paraspinal region, and blood cultures were negative for Pseudomonas. EG is typically classified as bacteremic or non-bacteremic in nature, and there are limited reports of panniculitis in the absence of bacteremia. This patient's presentation was unusual for the diffuse presentation of non-bacteremic EG with panniculitis. Due to the patient's past medical history of deep-seeded Pseudomonas infections, bacteria could have been directly inoculated into the skin at various injection sites. While EG is an uncommon but well-recognized dermatologic feature of Pseudomonas bacteremia, panniculitis is reportedly less commonly and likely underrecognized. Physicians should become aware of the cutaneous manifestations of underlying Pseudomonas infection so appropriate antibiotic therapy can be initiated.