Necrotizing Myositis: A Rare Necrotizing Soft Tissue Infection Involving Muscle

A Rare Necrotizing Soft Tissue Infection Involving Muscle

Harika Boinpally, MD; Raelina S. Howell, MD; Bebu Ram, MD; Virginia Donovan, MD; Michael Castellano, MD; Jon S. Woods, MD; Scott Gorenstein, MD, FACEP


Wounds. 2018;30(12):E116-E120. 

In This Article

Abstract and Introduction


Introduction: Necrotizing myositis (NM) is an extremely rare necrotizing soft tissue infection involving muscle. Unlike similar infections (eg, necrotizing fasciitis, clostridial myonecrosis) that can be more readily diagnosed, NM can have a benign presentation then rapidly progress into a life-threatening condition with a mortality rate of 100% without surgical intervention.

Case Report: A 74-year-old man with a history of prostate cancer with radiation therapy, seed implants, and 2 transurethral resection procedures presented to the emergency department after a fall. He was initially diagnosed and treated for urosepsis. Sixteen hours after presentation, he complained of pain and swelling of his right groin. Computed tomography of the abdomen and pelvis showed gas findings suspicious for necrotizing infection of the bilateral thighs. Surgical exploration revealed NM. Separate cultures from the left thigh and bladder grew Streptococcus intermedius, Clostridium clostridioforme, and Peptostreptococcus, suggesting a possible common source of infection from the prostate gland or the osteomyelitic pubic symphysis, which subsequently spread to the bilateral thighs.

Conclusions: To the best of the authors' knowledge, this is the first reported case of S intermedius and C clostridioforme causing NM. A high index of suspicion is required for extremely rare conditions like NM, because early diagnosis and surgical intervention significantly reduce mortality.


Necrotizing soft tissue infections (NSTIs) include a mild to aggressive spectrum of infections such as cellulitis, necrotizing fasciitis, and myositis involving dermis, subcutaneous tissue, fascia, and muscle.[1] Necrotizing fasciitis, a well-known NSTI, is a fascial infection which can progress to involve skin and muscle. In comparison, a lesser-known NSTI is necrotizing myositis (NM) that predominantly involves muscle and can later involve fascia and skin.[2] Necrotizing infections such as necrotizing fasciitis and clostridial myonecrosis are more readily diagnosed than NM, which requires a high index of suspicion. Necrotizing myositis is an extremely rare condition and also rarely reported. Prior literature has reported 30 cases over the last century,[3] and a literature search for NM revealed about 80 cases from 1958 through 2017. This NSTI has a mortality rate approaching 100% without surgical intervention.[1]

This report describes a case in which the patient presented with apparent urosepsis and was later found to have NM secondary to polymicrobial infection of Clostridium clostridioforme, Streptococcus intermedius, and Peptostreptococcus. To the best of the authors' knowledge, this is the first case of NM caused by C clostridioforme and S intermedius.