- Subcutaneous pyogenic infection of the pulp space compartments of the distal finger
- Do not mistake for pulp erythema due to paronychia or herpetic whitlow
- Infection typically begins with minor trauma to dermis overlying finger pad (e.g. foreign body such as a splinter)
- May spread to flexor tendon sheath, IP joint, or underlying periosteum
- The perinychium includes the nail, the nailbed, and the surrounding tissue.
- The paronychia is the lateral nail folds
- The hyponychium is the palmar surface skin distal to the nail.
- The lunula is that white semi-moon shaped proximal portion of the nail.
- The sterile matrix is deep to the nail, adheres to it and is distal to the lunule.
- The germinal portion is proximal to the matrix and is responsible for nail growth.
- Red, tense, and markedly painful distal pulp space
- May see necrotic appearing tissue distally due to increased pressure in space
- Bed bugs
- Closed fist infection (Fight Bite)
- Hand cellulitis
- Hand deep space infection
- Hand-foot-and-mouth disease
- Herpetic whitlow
- Flexor tenosynovitis
- X-ray to assess for foreign body
- Ultrasound can be utilized by placing the hand in a bowl of water and holding high frequency linear probe a few cm away from the finger (water is an excellent conductor)
- Gram stain and culture (chronic infections may be caused by atypical organisms)
- Usually a clinical diagnosis
Incision and drainage
- Perform digital block
- The incision should be made along the ulnar aspect of the index, middle, and ring fingers and along the radial aspects of the thumb and little finger.
- Number 11 blade is used to make incision on non-oppositional side of affected digit. Digital arteries and nerves arborize near the distal interphalengeal joint, minimizing risk of significant neurovascular damage.
- Start incision 5 mm distal to flexor DIP crease
- End incision 5 mm proximal to nail plate border
- Bluntly dissect and explore wound until abscess is decompressed
No need for packing
- DO NOT perform a "fishmouth" incision since this may result in: Unstable finger pad, neuroma, and/or loss of sensation
- Cephalexin 500mg PO q6hrs daily x 7 days
- TMP/SMX 2 DS tablets PO q12hrs x 7 days
- Clindamycin 450mg PO q8hrs x 7 days
- Dicloxacillin 250mg PO q6hrs daily x 7 days
- Discharge with follow-up in 2 days for wound check
- Refer to hand surgery only if systemically ill or concern for complicated infection
- Instruct patient to keep extremity elevated