Browse categories and answer follow-up questions to refine your symptom profile.
Approach to the Critical Patient
Immediate stabilization
Immediate priorities
Airway compromise
Oropharyngeal or neck bite
Facial swelling
Expanding hematoma
Hemorrhage
Pulsatile bleeding
Uncontrolled bleeding after direct pressure
Shock
Hypotension
Altered mental status
Anaphylaxis
Urticaria
Bronchospasm
Hypotension
Time critical threats
High risk bite patterns
Hand bite
Flexor tendon sheath involvement concern
Septic arthritis concern
Deep puncture
Retained tooth or foreign body concern
Deep space infection concern
Face and neck bite
Airway risk
Cosmetic and functional risk
Immunocompromised host
Rapid progression infection concern
Capnocytophaga sepsis risk
Isolation and exposure precautions
Zoonotic exposure precautions
Body fluid exposure
Gloves and eye protection
Wound irrigation splash precautions
Suspected rabid animal exposure
Local public health notification per policy
Early decision points
Key decisions
Rabies post exposure prophylaxis eligibility
Species and availability for observation or testing
Exposure category
Tetanus prophylaxis need
Vaccination history
Wound classification
Antibiotic prophylaxis indication
High risk wound features
High risk host features
Primary closure suitability
Location and time since bite
Infection signs
Consultation triggers
Early specialty involvement
Hand surgery
Hand bite with deep structure concern
Flexor tenosynovitis concern
Plastics
Face bite needing layered closure
Tissue loss
Orthopedics
Suspected joint penetration
Suspected osteomyelitis
Ophthalmology
Eyelid or globe proximity injury
Infectious diseases
Severe infection
Unusual host risk
Public health
Rabies risk assessment support
History
Core history elements
Exposure timeline and setting
Time since bite
Less than 8 hours
8 to 24 hours
More than 24 hours
Location of event
Urban
Rural
Travel outside region
Provoked vs unprovoked
Unprovoked aggression
Animal acting strangely
Animal details and rabies risk
Animal factors
Species
Dog
Cat
Human
Bat
Raccoon
Skunk
Fox
Rodent
Livestock
Ownership status
Known domestic
Unknown domestic
Wild
Availability
Available for 10 day observation
Available for testing
Not available
Vaccination status
Documented current
Unknown
Not vaccinated
Bite mechanics and wound contamination
Bite characteristics
Number of bites
Single
Multiple
Mechanism
Crush
Puncture
Tear or avulsion
Clothing barrier
No barrier
Thin barrier
Thick barrier
Saliva contamination
Visible saliva
Wound licked
Host risk factors
Patient risk factors
Immunocompromised state
Asplenia
Cirrhosis
Chemotherapy
Chronic steroids
HIV
Transplant
Diabetes
Poor glycemic control history
Peripheral vascular disease
Chronic limb ischemia
Lymphedema
Prior lymph node dissection
Prosthetic material near bite
Prosthetic joint
Vascular graft
Vaccination and prophylaxis history
Immunization status
Tetanus vaccination history
Last dose within 5 years
Last dose 5 to 10 years
Last dose more than 10 years
Unknown series completion
Prior rabies vaccination
Pre exposure series completed
Prior post exposure series completed
Symptoms suggesting infection or deep injury
Current symptoms
Pain progression
Increasing pain
Pain out of proportion
Functional impairment
Reduced range of motion
Weakness
Numbness
Systemic symptoms
Fever
Chills
Malaise
Local symptoms
Erythema spreading
Purulent drainage
Lymphangitic streaking
Physical Exam
Wound assessment
Local wound features
Location and depth
Hand and fingers
Face and scalp
Lower extremity
Tissue injury pattern
Puncture
Laceration
Avulsion
Contamination
Visible debris
Devitalized tissue
Infection signs
Erythema
Warmth
Swelling
Purulence
Crepitus
Neurovascular and functional exam
Distal function
Sensation
Two point discrimination if hand bite
Motor function
Tendon integrity
Grip strength limitation
Perfusion
Capillary refill
Distal pulses
Compartment features
Pain with passive stretch
Deep structure involvement
High risk findings
Joint involvement concern
Pain with passive range of motion
Effusion
Flexor tenosynovitis features
Fusiform swelling of digit
Finger held in flexion
Pain with passive extension
Tenderness along flexor sheath
Bone involvement concern
Point bony tenderness
Exposed bone
Systemic assessment
Systemic status
Vital signs abnormalities
Fever
Tachycardia
Hypotension
Sepsis features
Altered mental status
Poor perfusion
PITFALLS
Common misses
Small puncture with deep inoculation
Minimal surface findings early
Hand bite underestimation
Tendon sheath and joint proximity
Cat bite infection progression
Rapid onset cellulitis within 24 hours
Differential Diagnosis
Life threatening and limb threatening
Critical diagnoses
Necrotizing soft tissue infection
ICD-10 M72.6
Severe pain
Systemic toxicity
Sepsis
ICD-10 A41.9
Hypotension or organ dysfunction
Septic arthritis
ICD-10 M00.9
Pain with passive motion
Flexor tenosynovitis
SNOMED CT flexor tenosynovitis concept
Kanavel features
Mimics and alternate etiologies
Alternative diagnoses
Cellulitis non bite related
ICD-10 L03.90
Allergic reaction
ICD-10 T78.40XA
Fracture or dislocation
ICD-10 site specific fracture codes
Retained foreign body without infection
ICD-10 T16 to T19 site specific foreign body codes
Rabies related considerations
Rabies exposure outcomes
Rabies exposure without prophylaxis
Fatal encephalitis risk with true exposure
Alternative viral encephalitis
Non rabies etiologies in symptomatic patients
Laboratory Tests
Infection severity and sepsis evaluation
Infection labs
Complete blood count for systemic infection concern
Leukocytosis support for infection
Normal count does not exclude early infection
C reactive protein for deep infection concern
Trend utility for admitted patients
Lactate for sepsis concern
Elevated lactate supports hypoperfusion
Culture strategy
Microbiology tests
Wound culture for established infection
Purulent drainage sampling preferred
Superficial swab limitations
Blood cultures for systemic toxicity
Fever
Hypotension
Baseline safety monitoring
Medication safety labs
Creatinine and electrolytes for IV antibiotics
Dose adjustment need
Nephrotoxic regimen monitoring
Liver enzymes for hepatotoxic antibiotic concern
Amoxicillin clavulanate cholestatic risk context
PITFALLS
Test limitations
Normal inflammatory markers early in deep infection
Clinical exam priority
Negative culture after antibiotics
Culture before antibiotics when feasible in severe infection
Diagnostic Tests
Scoring Systems
Risk stratification tools
Rabies exposure category framework
Category 1
Touching or feeding animal
Licks on intact skin
Category 2
Nibbling of uncovered skin
Minor scratches without bleeding
Category 3
Transdermal bites or scratches
Saliva to mucosa
Bat exposure with uncertain contact
Tetanus prophylaxis algorithm
Clean minor wound
Td or Tdap if last dose 10 years or unknown
Tetanus immune globulin if unknown or incomplete series
Dirty or major wound
Td or Tdap if last dose 5 years or unknown
Tetanus immune globulin if unknown or incomplete series
MRI
MRI indications
Deep infection evaluation
Suspected osteomyelitis
Suspected deep abscess
Hand bite complications
Tenosynovitis extent
Septic arthritis extent
Performance and limits
High sensitivity for osteomyelitis
Limited availability for unstable patients
CT
CT indications
Facial bite with deep structural concern
Orbital involvement concern
Skull fracture concern
Deep space infection
Gas in soft tissue concern
Complex abscess mapping
Foreign body detection
Tooth fragments in deep tissue
Ultrasound (or US)
Ultrasound applications
Soft tissue abscess evaluation
Fluid collection identification
Guidance for drainage when appropriate
Foreign body evaluation
Radiolucent foreign body detection
Localized hyperechoic focus with shadowing
Vascular evaluation
Pseudoaneurysm concern near major vessel
Disposition
Admission and transfer criteria
Higher level care indications
Systemic toxicity
Sepsis physiology
Hemodynamic instability
Rapidly progressive infection
Spreading erythema despite initial care
Necrotizing infection concern
Deep structure involvement
Septic arthritis concern
Tenosynovitis concern
Osteomyelitis concern
High risk host
Immunocompromised
Asplenia
Advanced cirrhosis
Need for operative management
Extensive debridement need
Complex repair need
Discharge criteria
Safe discharge features
No systemic toxicity
Stable vital signs
No deep structure concern
Normal neurovascular exam
Preserved function
Reliable follow up
Reassessment within 24 to 48 hours if high risk
Clear prophylaxis plan
Rabies plan finalized with public health
Tetanus plan completed
Follow up planning
Follow up needs
Wound check timeline
24 to 48 hours for hand bites and punctures
48 to 72 hours for low risk wounds
Specialty follow up
Hand surgery for hand bites
Plastics for facial wounds
Treatment
Wound cleansing and repair
Local wound care
Irrigation and decontamination
High volume irrigation with sterile saline
Puncture wound irrigation focus
Devitalized tissue debridement when needed
Exploration and foreign body management
Depth evaluation in adequate anesthesia
Retained tooth fragment removal when identified
Closure strategy
Primary closure for selected low infection risk wounds
Delayed primary closure for higher risk wounds
Secondary intention for puncture and infected wounds
Hemostasis and dressing
Non adherent dressing
Elevation for hand injuries
Antibiotic prophylaxis and treatment
Antibiotic indications
Prophylaxis indications
Hand bite
Deep puncture
Crush injury
Face bite with primary closure
Immunocompromised host
Asplenia
Prosthetic joint or vascular graft proximity
Treatment indications
Established cellulitis
Abscess
Lymphangitis
Systemic symptoms
Oral antibiotic regimens
First line for dog and cat bites
Amoxicillin clavulanate adult
875 mg amoxicillin with 125 mg clavulanate PO every 12 hours
Duration 3 to 5 days prophylaxis
Duration 5 to 7 days uncomplicated cellulitis
Penicillin allergy non anaphylaxis
Cefuroxime PO
500 mg PO every 12 hours
Add metronidazole
500 mg PO every 12 hours
Penicillin allergy anaphylaxis
Doxycycline PO
100 mg PO every 12 hours
Avoid in pregnancy
Avoid in children under 8 years
Trimethoprim sulfamethoxazole PO
1 double strength tablet PO every 12 hours
Add clindamycin
300 mg PO every 6 to 8 hours
Human bite coverage option
Amoxicillin clavulanate adult
875 mg amoxicillin with 125 mg clavulanate PO every 12 hours
Duration 5 to 7 days prophylaxis
IV antibiotic regimens
Severe infection or deep structure concern
Ampicillin sulbactam
3 g IV every 6 hours
Adjust for renal function
Piperacillin tazobactam
4.5 g IV every 6 to 8 hours
Broad polymicrobial coverage
MRSA risk or severe purulence
Vancomycin
15 to 20 mg per kg IV every 8 to 12 hours
Trough based institutional protocol
Nephrotoxicity monitoring
Beta lactam anaphylaxis severe infection
Levofloxacin
750 mg IV every 24 hours
Add metronidazole
500 mg IV every 8 to 12 hours
Rabies post exposure prophylaxis
Rabies prophylaxis framework
Immediate steps
Copious wound irrigation as first line rabies prevention
Public health coordination for animal testing and observation
Post exposure prophylaxis for not previously vaccinated
Human rabies immune globulin
20 IU per kg once
Infiltrate as much as feasible into and around wound
Remaining volume IM at site distant from vaccine
Avoid same syringe and same anatomical site as vaccine
Rabies vaccine IM
Day 0
Day 3
Day 7
Day 14
Immunocompromised modification
Add day 28 dose
Serologic confirmation per public health
Post exposure prophylaxis for previously vaccinated
Human rabies immune globulin omission
Not indicated
Rabies vaccine IM
Day 0
Day 3
Tetanus prophylaxis
Tetanus prevention
Vaccine selection
Tdap preferred once in adulthood if not previously received
Td acceptable booster when Tdap already given
Tetanus immune globulin
250 IU IM once for indicated patients
Separate site from vaccine
Pain control and supportive care
Symptom management
Analgesia options
Acetaminophen PO
1000 mg PO every 6 to 8 hours
Maximum 3000 mg per day for most adults
Ibuprofen PO
400 mg PO every 6 to 8 hours
Avoid in renal failure and high bleeding risk
Immobilization
Splint for hand bite with pain and swelling
Elevation to reduce edema
Evidence levels and recommendations
Antibiotic prophylaxis evidence
High risk wounds benefit from prophylaxis
Hand bites
Cat bites
Deep puncture wounds
Immunocompromised hosts
ACEP Level C recommendation for prophylaxis in high risk bite wounds
Consensus based emergency wound management practice
Rabies prophylaxis evidence
Class I recommendation for rabies vaccine and immune globulin when exposure risk present
Public health guideline based
Tetanus prophylaxis evidence
Class I recommendation for tetanus booster and immune globulin based on wound and immunization history
Immunization guideline based
Special Populations
Pregnancy
Pregnancy considerations
Antibiotic selection
Amoxicillin clavulanate compatible in pregnancy
Doxycycline avoidance in pregnancy
Rabies prophylaxis
Rabies vaccine acceptable in pregnancy when indicated
Human rabies immune globulin acceptable in pregnancy when indicated
Tetanus prophylaxis
Tdap acceptable in pregnancy when indicated
Geriatric
Geriatric considerations
Higher complication risk
Delayed presentation
Comorbid vascular disease
Medication adjustments
Renal dosing adjustment for beta lactams
Fall risk considerations with sedating analgesics
Lower threshold for admission
Frailty
Limited self care capacity
Pediatrics
Pediatric considerations
Weight based antibiotics
Amoxicillin clavulanate
25 to 45 mg per kg per day amoxicillin component divided every 12 hours
Maximum per institutional pediatric dosing limits
Doxycycline age restriction
Avoid in children under 8 years unless specific indication
Rabies prophylaxis dosing
Human rabies immune globulin 20 IU per kg
Rabies vaccine schedule same as adults
Non accidental trauma concern
Injury pattern inconsistent with history
Safety assessment needs
Background
Epidemiology
Bite epidemiology
Common species
Dogs most common bites
Cats higher infection rate than dogs
Infection risk patterns
Hand bites higher infection risk
Puncture wounds higher infection risk
Pathophysiology
Microbiology and inoculation
Typical organisms
Pasteurella species
Rapid onset cellulitis association
Capnocytophaga canimorsus
Severe sepsis risk in asplenia and cirrhosis
Anaerobes
Polymicrobial infection common
Human bite organisms
Eikenella corrodens
Injury mechanics
Crushing injury tissue devitalization
Puncture inoculation into deep planes
Therapeutic Considerations
Treatment principles
Irrigation importance
Mechanical reduction of bacterial load
Antibiotic spectrum goals
Gram positive coverage
Gram negative coverage
Anaerobic coverage
Closure approach rationale
Primary closure infection risk tradeoff
Face wounds benefit from primary closure after adequate irrigation
Patient Discharge Instructions
copy discharge instructions
Discharge instructions
Wound care
Keep clean and dry for first 24 hours
Gentle washing with soap and water after 24 hours
Daily dressing change
Activity
Elevation for hand and extremity bites
Limit use if pain and swelling
Antibiotics
Take exactly as prescribed
Do not stop early unless instructed
Rabies plan
Follow public health instructions for vaccine appointments
Return immediately if unable to receive scheduled doses
Return to emergency criteria
Fever
Increasing redness or swelling
Pus or foul drainage
Red streaks up the limb
Worsening pain
Numbness or weakness
Trouble moving fingers or joints
New confusion or fainting
Follow up
Wound check in 24 to 48 hours for hand bites and punctures
Primary care follow up for tetanus series completion if needed
References
Clinical guidelines and key sources
Rabies prevention guidance
CDC rabies post exposure prophylaxis guidance
Vaccine schedule and immune globulin dosing
Skin and soft tissue infection guidance
IDSA guidance for bite wound infection management
Antibiotic selection and duration
Immunization guidance
National immunization guidance for tetanus prophylaxis by wound type
Booster and immune globulin indications
Coding and terminology
ICD-10 and SNOMED CT mapping
Dog bite
ICD-10 W54.0
Cat bite
ICD-10 W55.01
Other mammal bite
ICD-10 W55.81
Human bite
ICD-10 W50.3
Cellulitis
ICD-10 L03.90
Sepsis
ICD-10 A41.9
Necrotizing fasciitis
ICD-10 M72.6
Septic arthritis
ICD-10 M00.9
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.