Hand Infections

Many acute hand and upper extremity infections should be treated as surgical emergencies to avoid stiffness, contracture, pain, and amputation. Proper treatment requires understanding of anatomy and how this influences the behavior of certain infections, common offending organisms, antibiotic treatment, management of host factors, and surgical intervention. This article reviews the microbiology, antibiotic coverage, and surgical treatment of the most common infections in the hand: paronychia, felon, herpetic whitlow, flexor tenosynovitis, deep space infections, septic arthritis, bites from humans and animals, necrotizing fasciitis, mycobacterium infections, and fungal infections. Recommendations are based on the most recent available evidence.

Key points

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Acute hand infections are most commonly caused by Staphylococcus spp and Streptococcus spp, with an increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA).
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Empiric antibiotic coverage should be withheld until cultures have been obtained. Then it should begin with broad-spectrum treatment directed by the injury environment and mechanism, including strong consideration for coverage of MRSA.
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The cornerstone of surgical treatment includes incision, drainage, debridement, and irrigation followed by daily dressing changes.
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Herpetic whitlow is a viral infection that may mimic acute bacterial infections and typically resolves spontaneously without treatment.
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Flexor tenosynovitis can be diagnosed by the classic signs of fusiform swelling, flexed resting posture, flexor sheath tenderness, and pain with passive extension.
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Septic arthritis of the wrist is typically diagnosed by a joint aspirate white blood cell count greater than 50,000 with 75% polymorphonuclear lymphocytes. It should be treated as soon as possible.
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Bite injuries should always be explored for involvement of an underlying joint or tendon, especially human bite clenched fist injuries over the metacarpal head.
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Necrotizing fasciitis is a life-threatening condition with a mortality rate of 33% that requires emergent surgical debridement.