Septic (infective) conditions of the hand are rare but severe conditions. There’s always a form of trauma in the background, as well as some predisposing factors like malnutrition, immunodeficiency, diabetes, alcoholism, etc.

Treatment depends on the specific condition but often involves source control like incision and drainage, as well as antibiotics.

Paronychia

Paronychia is an infection of the soft tissue around the nail. The bacterium is often S. aureus. There is usually a trauma of the soft tissue, due to nail biting or puncture.

Symptoms include local pain, swelling, and erythema. Treatment involves antibiotics, as well as drainage if there’s an abscess.

Felon

Felon is an abscess of the finger pulp caused by infection by S. aureus or gram negatives following local trauma. Treatment is incision and drainage. It may lead to purulent tenosynovitis.

Purulent tenosynovitis

Purulent tenosynovitis is a bacterial infection of the flexor tendon sheath. Symptoms include pain, tenderness, erythema, swelling, and pain with passive extension. It’s a serious condition and an orthopaedic emergency which requires incision and drainage as well as IV antibiotics.

Horseshoe abscess is an abscess of the palmar space. It may occur due to spread from purulent tenosynovitis.

Herpetic whitlow

Herpetic whitlow is a viral infection of the hand caused by HSV-1. Symptoms include burning, erythema, and vesicular rash. Treatment is acyclovir.

Bite injury

Animal bites, including human bites, are often polymicrobial contaminated wounds. Antibiotics against both aerobic and anaerobic bacteria are used, and debridement may be necessary. Keep tetanus prophylaxis in mind.

Necrotising soft tissue infections

Necrotising soft tissue infections (of which necrotising fasciitis is one type) of the hand is also a severe condition and an orthopaedic emergency, and it may be life threatening. It may be polymicrobial or monomicrobial caused by clostridium perfringens, staphylococci, or streptococci. The patients will have both local and systemic symptoms of infection, as well as blackish discoloration and bullae. Treatment is antibiotics, debridement, hyperbaric oxygen chamber therapy, and possibly amputation.