Necrotizing fasciitis (NF) is the progressive necrosis of the skin and fascia and has morbidity and mortality rates of 70‐80%. The main causes of
mortality are septic shock, multiorgan failure, and delay in diagnosis and treatment. Microorganisms responsible for NF are often group A Streptococci,
Clostridium, and Bacteroides fragilis. Necrotizing fasciitis is a rare, life threatening soft tissue infection that requires emergency surgery and immediate
medical attention. In this case report, we present a case of NF and necrotizing pneumonia caused by Streptococcus pyogenes who was admitted to our
hospital with severe leg pain after intramuscular injection into the left gluteal region three days earlier.
Keywords: Necrotizing fasciitis, necrotizing pneumonia, Streptococcus pyogenes