Management: Human Bite (2-year-old biting a 5-year-old) - 5 Days After the Bite

A 5-day-old human bite in a child is a late-presenting wound and must be treated as infected until proven otherwise. This significantly changes the approach compared to a fresh bite.

1. Initial Assessment

History to document:

Exact time and date of the bite
Location of the wound on the body
Whether skin was broken / blood was visible
Any symptoms since the bite: pain, swelling, redness, pus, fever

Physical examination:

Location and size of the wound
Signs of infection: erythema, warmth, swelling, purulent discharge, lymphangitis, lymphadenopathy
Depth - assess for tendon, joint, bone, or vessel involvement
Neurovascular status distal to the wound

At 5 days post-bite, most wounds with any infection will already show clear signs. Absence of all signs is reassuring but antibiotics are still warranted if skin was broken.

2. Wound Care

Step	Action
Do NOT close the wound	Wounds >12-24 hours old (especially non-facial) should NOT be sutured primarily - significantly increased infection risk
Wound irrigation	Irrigate with copious sterile saline or clean water using moderate pressure. Avoid high-pressure irrigation of puncture wounds
Cleansing	Use 1% povidone-iodine or 1% benzalkonium chloride for soiled wounds
Debridement	Remove any superficial devitalized tissue and foreign material
Dressing	Apply appropriate moist wound dressing; assess daily
No tissue adhesive (Dermabond)	Never seal bite wounds with glue regardless of age or appearance - increases infection risk

Red Book (AAP), p. 324-325

3. Investigations

Wound swab for culture and sensitivity - mandatory at 5 days (signs of infection likely)
Blood culture if systemically unwell (fever, rigors, tachycardia)
X-ray if wound overlies a bone/joint, to look for: embedded tooth fragments, fracture, joint involvement, gas in tissues (anaerobic infection)

4. Antibiotic Treatment

Since the wound is 5 days old, empirical antibiotic therapy should be started immediately.

Target organisms in human bites:

Streptococcus viridans
Staphylococcus aureus
Oral anaerobes
Eikenella corrodens (characteristic of human bites)

Oral (mild-moderate infection, no systemic signs):

Patient	Drug	Dose	Duration
Child (no penicillin allergy)	Amoxicillin-clavulanate	22.5 mg/kg (amoxicillin component) BD	5-10 days
Child (penicillin allergy, <8 yrs)	TMP-SMX + Clindamycin	TMP 4-5 mg/kg/d div q12h + Clindamycin 10-20 mg/kg/d	10-14 days
Child (penicillin allergy, ≥8 yrs)	Doxycycline + Metronidazole	Doxycycline 2-4 mg/kg/d ± Metronidazole	10-14 days

Harriet Lane Handbook 23rd ed., p. 77 | RCH Melbourne Guidelines

IV (infected wound, systemic signs, or admission needed):

Option	Dose
Ampicillin-sulbactam	100-200 mg/kg/day IV divided q6h (max 3g/dose)
Ceftriaxone + Metronidazole	Ceftriaxone 50 mg/kg/day IV + Metronidazole 10 mg/kg TDS
Piperacillin-tazobactam	100 mg/kg IV q8h (max 4g/dose)

Modify antibiotics once culture results are available. MRSA is uncommon but consider if not responding.

5. Tetanus Prophylaxis

Check vaccination status of the 5-year-old
If immunization is up to date: no action needed
If incomplete or unknown: give tetanus toxoid (TT) +/- tetanus immunoglobulin (TIG) depending on wound type and immunization history

6. Bloodborne Virus (BBV) Risk Assessment

Human bites carry a small but real risk of bloodborne virus transmission (from biter's saliva/blood to bitten person).

Virus	Action
Hepatitis B (HBV)	Assess vaccination status of 5-year-old. If unvaccinated or incomplete series: give HBV vaccine (and consider HBV immunoglobulin [HBIG] if biter is HBsAg positive)
HIV	Risk from a bite is very low. If bloody saliva was involved or either child is at risk: consider HIV testing. PEP must be started within 72 hours - at 5 days, PEP is generally no longer indicated
Hepatitis C (HCV)	No post-exposure prophylaxis available; test and follow up if risk identified

At 5 days post-exposure, the HIV PEP window has closed (PEP is only effective if started within 72 hours). Baseline HIV testing of both children may still be considered for documentation.

Red Book 2021, p. 325

7. Indications for Surgical Referral / Hospital Admission

Refer or admit if any of the following:

Deep wound involving tendons, joints, bones, or deep fascia
Abscess formation
Necrotizing soft tissue infection or crepitus
Septic arthritis or osteomyelitis
Rapidly progressive infection or lymphangitis
Systemically unwell (fever, elevated WBC)
Wound on the hand, face, foot, or genitalia (special locations - higher risk)

8. Follow-Up

Review wound in 48-72 hours after initial management
Check culture results and adjust antibiotics accordingly
Daily wound inspection until healing is confirmed
If not improving on oral antibiotics: switch to IV and surgical review

Summary at a Glance

5-day-old human bite in a child
├── Assume INFECTED
├── Wound culture + swab
├── Do NOT close wound
├── Irrigate + debride + dress
├── Start Amoxicillin-clavulanate (oral) or Ampicillin-sulbactam (IV)
├── Check tetanus status
├── Assess HBV status → vaccinate if needed
├── HIV PEP window CLOSED at 5 days
└── Follow up in 48-72 hours; refer if severe

Sources: Red Book 2021 (AAP), Harriet Lane Handbook 23rd ed., RCH Melbourne Clinical Guidelines, Managing Human Bites - PMC

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