Describe Hand Infections in detail.

Definition & Importance

Hand infections are common and potentially serious: the hand’s tightly compartmentalised anatomy allows infection to spread rapidly along fascial planes and tendon sheaths, and delay or inadequate treatment can cause tendon necrosis, stiffness and permanent loss of function. Most follow a penetrating injury; the usual organism is Staphylococcus aureus.

Specific Infections

• Paronychia — infection of the nail fold, the commonest hand infection
• acute (usually staphylococcal) or chronic (often candidal, in those with wet hands).
• Felon — infection of the closed pulp space of the finger-tip
• the fibrous septa create a compartment, so pus produces intense throbbing pain and can cause pressure necrosis of the skin and underlying bone.
• Acute suppurative flexor tenosynovitis — infection within a flexor tendon sheath, a surgical emergency.

Management

General principles are elevation, rest/splintage, analgesia and appropriate antibiotics against Staph. Aureus, with early surgical drainage of any abscess (‘where there is pus, let it out’). A superficial paronychia may resolve with antibiotics or simple drainage of the nail fold; a felon and deep-space infections require incision and drainage; flexor tenosynovitis requires emergency sheath drainage and irrigation. After control of infection, early mobilisation and hand therapy restore movement and prevent stiffness.

Anatomy of Spread

The functional anatomy explains why hand infections are dangerous. The pulp of the finger-tip is divided by fibrous septa into a closed compartment, so a felon behaves like an abscess under pressure and can strangle the blood supply to the tip. The flexor tendons run in synovial sheaths that, in the little finger and thumb, communicate with the ulnar and radial bursae of the palm and can allow infection to track across the wrist (a ‘horseshoe abscess’). The deep palmar (thenar and mid-palmar) spaces are potential spaces where pus can collect and point dorsally. Understanding these planes guides where to look for spread and where to drain.

Prevention & Prognosis

Because outcome depends heavily on early treatment, the principles are prompt cleaning and appropriate care of every hand wound, tetanus prophylaxis, and a low threshold for exploring a wound that overlies a tendon sheath or joint. Human and animal bite wounds deserve particular respect — they are heavily contaminated (e.g. Pasteurella, Eikenella), should not be closed primarily, and need antibiotics and often surgical toilet. With early recognition and drainage most hand infections resolve fully; delay is the enemy of function.

Kanavel signs indicate flexor tendon sheath infection needing drainage.

• Rapid spread along sheaths/spaces → stiffness & loss of function; usually Staph. Aureus.
• Paronychia (nail fold), felon (pulp space compartment), web-space, deep-palmar-space infections.
• Flexor tenosynovitis = emergency; Kanavel signs (flexed finger, fusiform swelling, sheath tenderness, pain on extension).
• Elevation, antibiotics, and early drainage of pus; emergency sheath drainage for tenosynovitis.
• Follow with hand therapy to prevent stiffness.