Tropical Pyomyositis and Necrotizing Fasciitis

Abstract

Pyomyositis is a purulent infection of skeletal muscle that arises from hematogenous spread, usually with abscess formation. Necrotizing fasciitis is a more severe, rapidly progressive infection involving the superficial and deep fascia with necrosis and fluid collections that can be life threatening if left untreated. Both conditions may coexist, and concomitant cellulitis is often seen. A high incidence of these diseases occurs in the tropics, but they are increasingly being seen in temperate countries, due in part to their association with immunodeficiency conditions such as human immunodeficiency virus (HIV) infection, diabetes mellitus, and organ transplantation. This article aims to familiarize physicians with these entities, review their clinical manifestations and imaging features, and highlight the role of imaging in the management of patients with these conditions.

Multiple Abscesses in Thigh due to Klebsiella in a Diabetic Patient with Rheumatoid Arthritis

“…These include pneumonia, urinary tract infection, abdominal infection, soft tissue infection and infection of surgical sites and intravascular devices [1]. The incidence of Klebsiella infections is higher in diabetic patients [2][3][4]. The commonly reported infections in patients with rheumatoid arthritis are abscess (limb, perinephric, subdural, ovarian, cerebral, lung), pneumonia, empyema and pyelonephritis [5].…”

Magnetic resonance imaging of diabetic foot complications

“…(47) In pyomyositis, focal rim-enhancing lesions can be seen on a background of diffuse high T2-W signal (oedema), with associated irregular enhancement of the deep fascia. (48) …”

MRI in necrotizing fasciitis of the extremities

“…Both pyomyositis and necrotizing fasciitis may have similar clinical presentation of painful swelling and tenderness in the affected region. 4 In contrast to necrotizing fasciitis, pyomyositis is predominantly characterized by intramuscular abscess formation (Figure 9). Cases of infective myositis without abscess formation (Stage 1 pyomyositis) can also mimic reactive muscle changes in necrotizing fasciitis ( Figure 10).…”

“…The useful role of imaging in diagnosing necrotizing fasciitis has been highlighted in the literature, with reported high sensitivity and specificity of MRI. 1,2,4,5 This pictorial essay aims to review the MRI findings in necrotizing fasciitis, discuss its limitations and pitfalls and identify differentiating features from non-necrotizing soft-tissue infections, such as cellulitis and infective myositis/pyomyositis, conditions which may clinically mimic necrotizing fasciitis.…”