01Approach to the Critical Patient/attcp39

Key Concepts

›Subungual hematoma triage priorities

›Usually low-acuity presentation

›Identify high-risk features requiring urgent escalation

›Neurovascular status of digit is the primary safety check

›Alarm features mandating urgent evaluation

›Nail plate avulsion or subluxation from the eponychial fold

›Suggests open nail bed laceration or Seymour fracture

›Open fracture classification if periosteum violated

›Inability to actively extend DIP joint

›Mallet finger until proven otherwise

›Urgent orthopedic or hand surgery referral

›Inability to actively flex DIP joint

›Jersey finger (FDP avulsion) — requires surgical repair

›Do not delay specialist consultation

›Absent capillary refill or loss of 2-point discrimination

›Vascular or digital nerve injury

›Emergent hand surgery consultation

›Open fracture with exposed bone or open wound

›Antibiotic coverage initiated within 1 hour

›Orthopedic consultation for operative planning

PEARLS

›Key clinical pearls

›~25% of subungual hematomas have associated distal phalanx fracture

›X-ray all but the most trivial injuries

›Fracture with intact nail plate can still be treated non-operatively if undisplaced

›Seymour fracture is an open fracture — do not miss it in children

›Nail plate subluxed out of or beyond the eponychial fold is the key sign

02History/hx45

Mechanism and onset

›Injury mechanism

›Crush injury

›Door, hammer, heavy object

›Axial load (stubbed toe, dropped weight)

›Direct blow to nail unit

›Repetitive microtrauma

›Runners (toenail — "runner's toe")

›Ill-fitting footwear

Symptom characterization

›Pain profile

›Throbbing pain under the nail plate

›Pressure sensation beneath nail

›Severity guiding trephination decision

›Discoloration onset

›Dark red, purple, or black discoloration

›Time from injury to presentation

›Functional deficits

›Ability to flex and extend the DIP joint

›Grip strength loss or pinch deficit

Alarm features in history

›High-risk history elements

›Nail plate disruption or avulsion reported at time of injury

›Prior self-drainage attempts

›Non-traumatic origin of pigmentation

›Pigmentation present before any injury

›Gradual onset over weeks to months

›Delayed presentation (>48 hours)

03Physical Exam/exam48

Nail unit inspection

›Nail plate assessment

›Percentage of nail plate involved by hematoma

›Small (<25%), moderate (25-50%), large (>50%)

›Size alone does not determine need for nail removal

›Nail plate integrity

›Intact vs. cracked, fractured, or avulsed

›Subluxation from the eponychial fold (Seymour fracture sign)

›Surrounding nail fold disruption

›Paronychia or periungual laceration

›Proximal nail fold elevation or disruption

Neurovascular examination

›Digital neurovascular status

›Capillary refill of the fingertip

›Normal <2 seconds

›Compare with contralateral digit

›2-point discrimination

›Normal <6 mm at fingertip pulp

›Assess radial and ulnar aspects of digit

›Skin color and temperature

›Pallor or cyanosis of fingertip

Range of motion and stability

›DIP joint active range of motion

›Active extension

›Inability to actively extend DIP = mallet deformity until ruled out

›Extensor lag measured in degrees

›Active flexion

›Inability to actively flex DIP = jersey finger until ruled out

04Differential Diagnosis/ddx41

Traumatic differentials

›Nail bed laceration (S61.0)

›Coexists with subungual hematoma in up to 50% of cases with disrupted nail plate

›Suspect when nail plate is cracked, avulsed, or elevated

›May require nail removal and primary nail bed repair

›Distal phalanx fracture (S62.5)

›Tuft fracture most common — comminuted, usually stable

›Transverse shaft fracture — may be unstable with displacement

›Intra-articular DIP fracture — requires orthopedic assessment if >1/3 articular surface

›Mallet finger (S63.2)

›Extensor tendon avulsion at distal phalanx

›Unable to actively extend DIP joint

›May have bony avulsion fragment (bony mallet)

›Jersey finger (S62.9)

›FDP avulsion from distal phalanx

›Unable to actively flex DIP joint

›Requires surgical reattachment — do not delay referral

›Seymour fracture (S62.5 in pediatrics)

›Salter-Harris I or II fracture of distal phalanx physeal plate

›Nail plate subluxed out of or proximal to the eponychial fold

›Open fracture — requires OR management and antibiotics

Non-traumatic differentials (cannot-miss)

›Subungual melanoma (C43.7 or C44.7)

›Acral lentiginous melanoma — most common in darker-skinned populations

›Hutchinson sign, irregular longitudinal pigment bands, no history of trauma

›Does not migrate distally with nail growth — key differentiating feature

›Dermatology referral for biopsy

›Glomus tumor (D21.1)

05Laboratory Tests/lt23

Routine labs

›Routine labs for simple isolated hematoma

›Not indicated for uncomplicated subungual hematoma

›No pre-procedure labs required for trephination

Infection workup

›Labs for suspected secondary infection (delayed presentation)

›Complete blood count

›Leukocytosis suggests spreading infection or osteomyelitis

›Thrombocytopenia affects healing and antibiotic choice

›C-reactive protein and erythrocyte sedimentation rate

›Elevated in osteomyelitis or septic arthritis

›Blood cultures

›If systemic sepsis features present (fever, tachycardia, rigors)

›Wound culture

›Swab or tissue if purulent drainage present

›Guide antibiotic de-escalation

Coagulation workup

›Labs for suspected bleeding diathesis

›Prothrombin time and INR

›Warfarin users or liver disease

›Activated partial thromboplastin time

›Factor deficiency screen (hemophilia A/B)

›Platelet count

›Thrombocytopenia predisposes to expansive hematoma

›von Willebrand antigen and activity

›If vWD suspected from history of mucocutaneous bleeding

06Diagnostic Tests/dt68

Scoring Systems

›Subungual hematoma management decision framework

›No universally validated scoring tool exists for subungual hematoma management

›Clinical stratification guides management

›Simple: intact nail plate, no nail fold disruption, no fracture — trephination alone

›Complex: nail plate disruption, nail fold injury, or displaced/open fracture — nail removal and nail bed repair

›Hematoma size threshold controversy

›Historical 50% rule (remove nail if >50% involved) not supported by current evidence

›Seaberg prospective study (Am J Emerg Med, 1991): trephination alone satisfactory regardless of size when nail plate intact

›Nail bed integrity, not hematoma size, determines need for removal

Plain Radiograph

›Plain X-ray of digit (AP and lateral views)

›Indication

›Recommended for all but the most trivial subungual hematomas

›~25% of subungual hematomas have associated distal phalanx fracture (AFP, 2022)

›Key findings to identify

›Tuft fracture — comminuted, usually stable, treated non-operatively

›Transverse shaft fracture — may require splinting or surgical fixation

›Intra-articular DIP fracture — referral if >1/3 articular surface or displaced

›Physeal fracture (Seymour) — widened physis in a child with nail subluxation

›Subungual exostosis — bony protrusion from distal phalanx

›Limitations

›Nail bed laceration not visible on plain film

›Soft tissue injury requires clinical assessment

Scoring Systems (continued 1)

›Nail involvement estimation

›Visual estimation of percentage involvement

›No validated tool; clinical gestalt used

07Disposition/dispo36

Discharge criteria

›Standard discharge criteria

›Intact neurovascular examination

›No associated open fracture

›No tendon injury (mallet or jersey finger)

›No Seymour fracture in pediatric patient

›Pain adequately controlled

›Patient able to follow discharge instructions and return precautions

Consultation and admission triggers

›Hand surgery referral indications

›Complex nail bed laceration requiring repair

›Nail plate disruption with suspected nail bed injury

›Stellate or complex lacerations

›Open fracture of distal phalanx

›Requires OR irrigation, debridement, and antibiotics

›Seymour fracture (pediatric)

›Technically open fracture — OR-level care

›Displaced or angulated distal phalanx fracture

›Intra-articular fracture involving >1/3 articular surface

›Mallet finger with large bony fragment or >30% articular surface

›Jersey finger — all cases require surgical referral

›Dermatology referral indications

›Suspected subungual melanoma

›Non-traumatic pigmentation not migrating with nail growth

›Hutchinson sign present

›Suspected glomus tumor

›Positive Love's or Hildreth's test

›Confirm with MRI, then refer for surgical excision

08Treatment/t76

Immediate analgesia

›Pain management

›Ibuprofen 400-600 mg PO every 6-8 hours

›NSAID as first-line for acute traumatic pain

›Take with food to reduce GI side effects

›Acetaminophen 500-1000 mg PO every 6-8 hours

›Alternative if NSAID contraindicated

›Maximum 4000 mg per 24 hours (hepatic dosing <2000 mg/day)

›Digital nerve block for procedural analgesia

›1% or 2% lidocaine without epinephrine, 1-2 mL per web space

›Volar and dorsal digital nerve approach

›Onset 5-10 minutes; duration 60-90 minutes

Trephination procedure

›Nail trephination (decompression)

›Indications

›Painful subungual hematoma regardless of size if nail plate intact

›Hematoma >25% with significant symptoms

›Best performed within 48-72 hours of injury while hematoma remains liquid

›Technique options

›Heated paperclip or electrocautery device

›Heat until red-hot; gently apply over nail until blood egresses

›Multiple holes may be needed for adequate drainage

›CONTRAINDICATED with acrylic or artificial nails (41.5% ignition rate)

›18-gauge needle (manual rotation)

›Rotate needle through nail plate with gentle pressure

›Preferred for acrylic nails or when electrocautery unavailable

›Extra-fine insulin syringe needle (27-gauge)

›Dermatologic Surgery (2003): effective and atraumatic technique

›Particularly useful in children

›Post-procedure care

›Gentle pressure to encourage drainage

›Wound cleaned with saline or antiseptic

›Non-adherent dressing applied

›Splint if associated fracture

Nail removal and nail bed repair

›Nail removal indications

›Nail plate disrupted, cracked, or subluxed from eponychial fold

›Suspected underlying nail bed laceration requiring repair

›Open fracture of distal phalanx with nail plate involvement

›Nail removal technique

›Digital block anesthesia first

›Blunt nail elevator or iris scissors to elevate nail plate from proximal fold

›Preserve nail plate for re-implantation as biologic dressing

›Irrigate nail bed with saline

›Nail bed repair

›Absorbable sutures (5-0 or 6-0 chromic gut or polyglactin 910)

›Re-implant nail plate under the proximal nail fold after repair

›Nail plate acts as biologic stent to maintain fold patency

›Secure with 4-0 nylon sutures through nail plate

›Alternative: non-adherent petrolatum gauze if nail not salvageable

›Evolving evidence: non-operative management may yield comparable outcomes

›Annals Plastic Surgery (2022): non-operative management vs. standard repair — similar functional outcomes

›Discuss with hand surgery when uncertain

Wound care and infection prevention

›Wound care

›Non-adherent dressing changed every 24-48 hours

›Elevation of hand above heart level for first 48 hours

›Reduces swelling and throbbing

›Ice application (wrapped) for first 24-48 hours

›20 minutes on, 20 minutes off

›Tetanus prophylaxis

›Tdap booster if last dose >5 years ago for contaminated wound

›Tdap booster if last dose >10 years ago for clean wound

›Tetanus immunoglobulin (TIG) 250 units IM if unimmunized and contaminated wound

›Lancet (2026): tetanus prophylaxis protocols in traumatic wounds

›Antibiotics

›Not routinely indicated for simple subungual hematoma

›Indicated for open fracture

›Cephalexin 500 mg PO every 6 hours for 5 days

›Cefazolin 1 g IV every 8 hours if open fracture being managed operatively

›Clindamycin 300-450 mg PO every 6-8 hours if penicillin allergic

›J Trauma Acute Care Surgery (2024) guidelines: prophylactic antibiotics for open fractures

Splinting

›Immobilization indications and technique

›Distal phalanx fracture: dynamic splinting or aluminum finger splint

›DIP immobilized in slight flexion (10-20 degrees) for tuft fracture

›Duration: 3-4 weeks for comfort

›Mallet finger: stack splint or dorsal aluminum splint

›DIP joint in full extension or slight hyperextension

›Duration: 6-8 weeks continuous wear, then 4 weeks night splinting

›No splint required for simple trephination without fracture

09Special Populations/sp62

Pregnancy

›Pregnancy-specific considerations

›Mechanism and presentation unchanged in pregnancy

›Trephination safe at all gestational ages

›Local anesthetic: lidocaine without epinephrine preferred

›Lidocaine Category B — safe for digital nerve block

›Epinephrine: avoid for digital blocks in all patients (vasoconstriction risk)

›Analgesic modifications

›Acetaminophen preferred over NSAIDs in third trimester

›NSAIDs risk premature closure of ductus arteriosus after 30 weeks

›Ibuprofen acceptable in first and second trimesters with caution

›Antibiotic selection if needed

›Cephalexin: Category B, safe in pregnancy

›Clindamycin: generally safe, used for penicillin allergy

›Avoid fluoroquinolones and tetracyclines

›Tetanus prophylaxis

›Tdap recommended in pregnancy (27-36 weeks preferred)

›Safe to administer if wound indication arises

Geriatric

›Geriatric-specific considerations

›Fall-related crush injury is common mechanism in elderly

›Rule out underlying fragility fracture (osteoporosis)

›Anticoagulation considerations

›Higher prevalence of anticoagulant use in elderly

›Larger hematomas expected; does not change trephination indication

›Do not discontinue anticoagulation without risk-benefit assessment

›Skin and nail fragility

›Nail plates thicker and more brittle in elderly

›Onychomycosis common; can complicate trephination

›Skin tears around nail fold more likely during manipulation

›Analgesic dosing modifications

›Ibuprofen: use with caution

›Renal impairment risk; GI bleeding risk higher in elderly

›Consider acetaminophen as preferred first-line

›Opioids: reserve for severe uncontrolled pain; fall risk

›Infection risk

›Diabetes and peripheral vascular disease prevalent in elderly

›Lower threshold for antibiotic prophylaxis in open wounds

›Non-traumatic pigmented nail lesions

›Subungual melanoma incidence increases with age

›Higher index of suspicion for any unexplained subungual pigmentation

Pediatrics

›Pediatric-specific considerations

›Crush injuries from doors are the most common mechanism in children

›Pediatric Emergency Care (2014): high prevalence in ED setting

›Seymour fracture — cannot miss diagnosis in children

›Salter-Harris I or II fracture of distal phalanx physis

›Nail plate subluxed proximal to the eponychial fold (key sign)

›Represents open fracture — requires surgical irrigation and debridement

›Antibiotics: cephalexin 25-50 mg/kg/day divided every 8 hours (max 500 mg/dose)

›Plastic Reconstructive Surgery (2018): treatment algorithm and surgical outcomes

›Non-accidental trauma consideration

›Inconsistent mechanism with injury pattern warrants safeguarding assessment

›Collect collateral history from multiple sources

›Growth plate considerations

›All distal phalanx fractures in skeletally immature patients involve physis potentially

›X-ray is mandatory; comparison views of contralateral digit may aid interpretation

›Analgesic dosing

›Ibuprofen 10 mg/kg PO every 6-8 hours (max 400 mg/dose)

›Acetaminophen 15 mg/kg PO every 4-6 hours (max 1000 mg/dose)

›Weight-based dosing mandatory

›Trephination in children

›Extra-fine insulin syringe needle preferred for atraumatic technique

›Procedural anxiolysis: intranasal dexmedetomidine 1-2 mcg/kg or midazolam 0.5 mg/kg intranasal (max 10 mg)

›Topical anaesthetic (EMLA) 60 minutes prior for needle-based trephination

10Background/b66

Epidemiology

›Incidence and prevalence

›One of the most common hand injuries in the ED and primary care settings

›No precise population incidence reported; crush injuries to digit are ubiquitous

›Associated distal phalanx fracture rate

›~25% of subungual hematomas have associated fracture

›AFP (2022): Childress et al., common finger fractures review

›Fingertip injuries overall prevalence

›Account for up to 10% of all acute hand injuries in the ED

›Most common occupational hand injury

›Demographics

›Any age affected; pediatric crush injuries (doors) extremely common

›Occupational predominance: carpenters, mechanics, construction workers

›Athletic populations: ball sports, rock climbing, racquet sports

›Runners: repetitive microtrauma to toenails (runner's toe)

›ICD-10 coding

›S60.10 — contusion of unspecified finger (unspecified nail)

›S60.11 through S60.19 — contusion of specific fingers

›L60.8 — other nail disorders (subungual hematoma without fracture)

›S62.5 — fracture of distal phalanx (when associated fracture present)

Pathophysiology

›Mechanism of hematoma formation

›Crush or direct blow compresses the highly vascularized nail bed against the rigid distal phalanx

›Nail bed (sterile matrix and germinal matrix) is rich in glomus bodies

›Rapid pressure rise causes rupture of nail bed microvasculature

›Blood accumulates in the subungual space between nail plate and nail bed

›Enclosed space creates pressure-related throbbing pain

›Hematoma may dissect proximally under the nail fold

›Nail anatomy relevant to pathophysiology

›Germinal matrix: proximal nail bed responsible for 90% of nail plate production

›Injury here causes permanent nail deformity

›Sterile matrix: distal nail bed that adheres nail plate

›Lacerations here most commonly repaired to preserve cosmetic outcome

›Nail plate: keratin structure that protects sterile matrix

›Acts as protective roof; disruption exposes nail bed

›Hyponychium: seal at distal free edge; barrier to infection

›Paronychium: lateral nail fold; paronychia can complicate nail injuries

›Fracture mechanism

›Tuft fracture: comminuted fracture of distal phalanx under crush load

›Periosteum usually intact — closed fracture in most cases

›Nail plate acts as biologic splint for nail bed

›Open fracture scenario: nail plate displacement exposes fracture site

›Any nail plate disruption with underlying fracture = potential open fracture

›Seymour fracture: physeal plate shear with interposed soft tissue

Therapeutic Considerations

›Trephination evidence base

›Seaberg et al. (Am J Emerg Med, 1991): prospective study of trephination

›Trephination alone yielded excellent outcomes regardless of hematoma size

›No benefit from nail removal when nail plate intact and no associated nail fold injury

›Traditional 50% rule (remove nail if >50% size): not supported by current evidence

›AFP guideline (2025, Hilgefort et al.): nail integrity, not size, drives management decision

›Non-operative management of nail bed injuries

›Annals Plastic Surgery (2022): non-operative management compared to standard nail bed repair

›Comparable functional and cosmetic outcomes at follow-up

›Reduced procedural complexity and patient discomfort

›Evidence supports observation for intact nail plate even when fracture is present

›Infection risk following trephination

›Infection rate from trephination is low when performed aseptically

›No evidence that routine antibiotics after trephination reduce infection

›Open fractures are a distinct indication for prophylactic antibiotics

›Electrocautery safety

›Western J Emergency Medicine (2022, Blereau et al.): acrylic nail ignition study

›41.5% ignition rate with electrocautery near acrylic nails

›Use 18-gauge needle or heated paperclip for acrylic nail patients

›Nail regrowth and cosmesis

›Fingernail grows approximately 3 mm/month; complete regrowth 3-6 months

›Toenail grows approximately 1.5 mm/month; complete regrowth 6-12 months

›Cosmetic outcome after trephination alone is generally excellent

›Nail may fall off spontaneously as hematoma resolves

11Patient Discharge Instructions/pdi32

copy discharge instructions

›Diagnosis and procedure explanation

›You have a subungual hematoma — a blood blister under your nail caused by a crush or impact injury

›A small hole was made in your nail (trephination) to drain the blood and relieve pressure

›The nail may fall off on its own over the coming weeks — this is expected

›A new nail will grow back; this typically takes 3-6 months for fingernails and 6-12 months for toenails

›Wound and nail care instructions

›Keep the finger elevated above heart level for the first 48 hours to reduce swelling

›Apply ice wrapped in cloth for 20 minutes every 1-2 hours for the first 24 hours

›Keep the wound clean and dry; change dressing every 24-48 hours

›Soak in warm soapy water twice daily starting 48 hours after the procedure

›Leave any sutures in place as directed; follow-up for removal if non-absorbable sutures placed

›Activity restrictions

›Avoid activities that stress the injured digit until pain resolves

›Return to sport and heavy manual work as tolerated — no fixed restriction for trephination alone

›If a fracture or tendon injury was also diagnosed, follow the specific instructions given

›Medications

›Take ibuprofen 400-600 mg every 6-8 hours with food for pain (unless told otherwise)

›Acetaminophen 500-1000 mg every 6-8 hours can be alternated if needed

›Do not exceed recommended doses of acetaminophen (max 4000 mg per day)

›Continue any prescribed antibiotics for the full course

›Return to emergency department immediately if

›Increasing pain, redness, swelling, or warmth in the finger

›Pus or foul-smelling discharge from the nail or wound

›Fever above 38 degrees Celsius

›Numbness or tingling that is getting worse

›Inability to bend or straighten the fingertip

›Streak of redness spreading up the finger or hand

12References/r51

Guidelines and key sources

›Fingertip Injuries (AFP, 2025)

›Hilgefort J, Becker J, Chu J

›American Family Physician, 2025

›PMID: 40736493

›Approach to Nail Trauma for Primary Care Physicians (Can Fam Physician, 2023)

›Lafreniere AS, Misati G, Knox A

›Canadian Family Physician, 2023

›PMID: 37704235

›Fingertip Injuries: A Review and Update on Management (JAAOS, 2024)

›De Ruiter BJ, Finnan MJ, Miller EA, Friedrich JB

›Journal of the American Academy of Orthopaedic Surgeons, 2024

›PMID: 39602800

›Treatment of Subungual Hematomas With Nail Trephination (Am J Emerg Med, 1991)

›Seaberg DC, Angelos WJ, Paris PM

›American Journal of Emergency Medicine, 1991

›PMID: 2018587

Supporting references

›Common Finger Fractures and Dislocations (AFP, 2022)

›Childress MA, Olivas J, Crutchfield A

›American Family Physician, 2022

›PMID: 35704814

›Rethinking the Need for Nail Plate Removal (Ann Plast Surg, 2022)

›Rao V, Akiki RK, Crozier JW, et al

›Annals of Plastic Surgery, 2022

›PMID: 35513322

›Salter-Harris Fractures of the Distal Phalanx (Plast Reconstr Surg, 2018)

›Gibreel W, Charafeddine A, Carlsen BT, Moran SL, Bakri K

Evidence & Review

Evidence & Review