This patient is suffering from necrotizing fasciitis. He needs empiric broad antibiotic coverage and surgical debridement of necrotic tissues.
Necrotizing fasciitis is a rapidly progressive bacterial infection of the deep soft tissues. Organisms involved include streptococcus pyogenes, mixed anaerobes, and gram-negative rods. Bacteria are generally introduced into the soft tissues during surgery, minor trauma (small puncture wound) or any open trauma. The infection can progress over minutes to days and result in profound tissue damage and death.
Headley summarizes necrotizing soft tissue infections in the primary care setting. She emphasizes that early diagnosis and rapid treatment are critical to prevent loss of limb or death. While there is no pathognomonic sign, patients may present with some evidence of cellulitis, vesicles, bullae, edema, crepitus, erythema, and fever. Reported pain may seem out of proportion to the physical finding and as the infection progresses, their pain may decrease.
O'Loughlin et al., in a report on the epidemiology of Group A Strep infections, reported a 24% mortality rate among necrotizing fasciitis cases reported to the CDC from 10 states in US between 2000 and 2004.
Image A depicts necrotizing fasciitis in the left leg. Note the purplish discoloration of the skin surrounded by an area of cellulitis.
Answers 1, 2, & 3: Failure to treat immediately with empiric antibiotics and surgical debridement will increase the risk of mortality and loss of limb or life.
Answer 5: While amputation may ultimately be necessary, serial debridement of affected tissues over the first several days is a better strategy for preserving limb function.
Headley AJ. Necrotizing soft tissue infections: a primary care review. Am Fam Physician. 2003 Jul 15;68(2):323-8. Review. PubMed PMID: 12892352.
PMID:12892352 (Link to Abstract)
O'Loughlin RE, Roberson A, Cieslak PR, Lynfield R, Gershman K, Craig A, Albanese BA, Farley MM, Barrett NL, Spina NL, Beall B, Harrison LH, Reingold A, Van Beneden C; Active Bacterial Core Surveillance Team. The epidemiology of invasive group A streptococcal infection and potential vaccine implications: United States, 2000-2004. Clin Infect Dis. 2007 Oct 1;45(7):853-62. Epub 2007 Aug 29. PubMed PMID: 17806049.
PMID:17806049 (Link to Abstract)