Surgical - Subungual haematoma

Indications

Painful subungual haematoma

Contraindications (absolute in bold)

Spontaneous drainage

Acrylic nails (avoid hot cautery due to risk of ignition)

Injury >48 hours old (haematoma clotted)

Alternatives

Simple analgesia (e.g. oral paracetamol and ibuprofen)

Informed consent

Verbal consent

Less complex non-emergency procedure with low risk of complications

Potential complications

Pain

Failure (drainage hole too small or coagulation of blood)

Onycholysis (separation of the nail plate from the nail bed)

Nail bed injury or tattooing with carbon particles (hot cautery)

Infection

Procedural hygiene

Standard precautions

Aseptic non-touch technique

PPE: non-sterile gloves, protective eyewear

Area

Procedure room, bed or chair space

Staff

Procedural clinician

Equipment

18-21g needle, paper clip or electrocautery tool

Flame (if using paper clip)

Saline

Gauze

Positioning

Sitting or lying with affected hand or foot placed on a flat and firm surface

Medication

None

Sequence (needle method)

Twirl needle with slow downward pressure until loss of resistance and drainage is seen (avoiding nail bed injury)

Multiple holes may be necessary to facilitate adequate drainage

Allow the haematoma to drain, gentle squeezing the tip of the finger to facilitate drainage

Irrigate wound with saline

Sequence (hot cautery)

Straighten the end of a paper clip and heat with a flame or activate a cautery tool

Place the hot end on the nail over the centre of the haematoma

Apply gentle pressure until the nail is breached and haematoma expressed (avoid nail bed injury)

Allow the haematoma to drain, gentle squeezing the tip of the finger to facilitate drainage

Irrigate wound with saline

Post-procedure care

Treatment:

Assess extensor tendon function for disruption (mallet finger), capillary refill and sensation

Apply an absorbent dressing and advise to keep dry for two days

X-ray phalanx (if distal phalanx fracture, splint with the DIP joint in extension and elevate for 48 hours)

Non-displaced distal phalanx fractures should be splinted with the DIP joint in extension for three to four weeks

Displaced or intra-articular distal phalanx fractures require referral to a surgeon

Patient advice:

Recommend oral pain relief with paracetamol and Ibuprofen

Keep the affected digit clean and dry

The nail may fall off during the week following haematoma drainage

Return if re-accumulation with pain or signs of infection (warmth, redness, excessive swelling, fever)

Tips

Heating a paper clip or cautery tool allows easy passage through the nail

Drainage is usually painless and does not usually require local anaesthesia with a ring block

Take care not to penetrate too far and traumatise the nail bed

Discussion

Subungual haematoma causes pressure build up in a contained space with significant pain which can be immediately relieved by drainage.

Drainage is indicated even if the haematoma is associated with an underlying phalanx fracture and nail bed laceration (open fracture). Infection appears to be a rare occurrence and routine prophylactic antibiotics are not required, although these can be considered for confirmed fractures and immunocompromised patients.

A subungual haematoma that is already draining does not require trephination, however disruption of the nail fold (edges) indicates a higher chance of significant nail bed laceration. We recommend these injuries are referred to your local hand team for consideration of nail removal and nail bed repair.

Peer review

This guideline has been reviewed and approved by the following expert groups:

Emergency Care Institute

Please direct feedback for this procedure to ACI-ECIs@health.nsw.gov.au.

References

Roberts JR, Custalow CB, Thomsen TW. Roberts and Hedges' clinical procedures in emergency medicine and acute care. 7th ed. Philadelphia, PA: Elsevier; 2019.

Dunn RJ, Borland M, O'Brien D (eds.). The emergency medicine manual. Online ed. Tennyson, SA: Venom Publishing; 2019.

Fastle RK, Bothner J. Subunghual haematoma. In: UpToDate. Waltham (MA): UpToDate. 2018 Jul 5. Available from: https://www.uptodate.com/contents/subungual-hematoma

Dean B, Becker G, Little C. The management of the acute traumatic subungual haematoma: a systematic review. Hand Surg. 2012;17(1):151-154. doi:10.1142/S021881041230001X

Pingel C, McDowell C. Subungual hematoma drainage. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2020.

Bonisteel PS. Practice tips. Trephining subungual hematomas. Can Fam Physician. 2008;54(5):693.

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