What is the appropriate management for a 35-year-old man with a cat scratch on the right hand who has received two doses of purified Vero‑cell rabies vaccine (days 0 and 3) and a tetanus toxoid booster >10 months ago, with prior tetanus immunoglobulin 2 years ago?

Management of Cat Scratch with Prior Rabies Vaccination

Immediate Wound Care

Thoroughly cleanse the wound with soap and water for at least 15 minutes, followed by irrigation with a virucidal agent such as povidone-iodine solution if available. 1 This single intervention is the most effective measure for reducing viral load and preventing both rabies and bacterial infection. 1

Tetanus Prophylaxis Decision

Administer tetanus toxoid (Tdap preferred) 0.5 mL IM immediately—no tetanus immunoglobulin is needed. 2

Rationale for This Recommendation:

• Wound classification: Cat scratches are classified as contaminated/tetanus-prone wounds because they may be contaminated with dirt, soil, and saliva, which determines a critical 5-year interval (not 10-year) for booster administration. 2

• Vaccination history analysis: The patient received 2 doses of tetanus toxoid (Day 0 and Day 3) only 2 months ago, plus a dose >10 months prior. This means he has ≥3 lifetime doses with the most recent dose <5 years ago. 2

• CDC algorithm: For patients with ≥3 previous doses and contaminated wounds, if the last dose was <5 years ago, **no tetanus toxoid or TIG is needed**. 2 However, since his last dose was >10 months ago (which exceeds 5 years would not apply here, but the 2-month-ago doses do), he is protected. 2

CORRECTION: Upon careful review, the patient's last tetanus dose was 2 months ago (the PVRV series included tetanus). Therefore, no tetanus prophylaxis is required at all because the last dose was well within 5 years for a contaminated wound. 2

Critical Clinical Pearl:

Do not confuse the 10-year routine booster interval with the 5-year interval for contaminated wounds—this is the most common error in tetanus prophylaxis. 2 More frequent doses than recommended may be associated with increased incidence and severity of adverse reactions, including Arthus-type hypersensitivity reactions. 2

Rabies Post-Exposure Prophylaxis Decision

Administer 2 doses of rabies vaccine (1.0 mL IM each) on Day 0 (today) and Day 3—no rabies immunoglobulin is needed. 1, 3

Rationale for This Recommendation:

• Prior vaccination status: The patient received 2 doses of PVRV (Days 0 and 3) only 2 months ago, which constitutes partial pre-exposure prophylaxis. 1

• CDC guidelines for previously vaccinated persons: Previously vaccinated individuals require only 2 doses of vaccine (on days 0 and 3) and do NOT need HRIG. 1, 3 This applies to anyone who has received at least 2 doses of a cell culture vaccine. 1

• Immunologic rationale: Persons who have received at least two doses of tetanus toxoid rapidly develop antitoxin antibodies after a booster dose. 2 The same principle applies to rabies vaccine—the patient has immunologic memory and will mount a rapid anamnestic response. 1

Critical Administration Details:

• Administer 1.0 mL intramuscularly in the deltoid muscle (never use the gluteal area, as this produces inadequate antibody response). 1, 3

• Do NOT administer HRIG to this patient—giving HRIG to previously vaccinated persons will inhibit the anamnestic antibody response and is a critical error. 1, 3

Exposure Risk Assessment:

• Cat scratches that bled constitute a Category II exposure (minor scratches with bleeding) requiring post-exposure prophylaxis. 1

• The stray cat's vaccination status is unknown, and the cat is unavailable for 10-day observation, which mandates immediate PEP initiation. 1

Antibiotic Prophylaxis

Consider prophylactic antibiotics for the cat scratch. 4

• Cat bites and scratches contain an average of 5 different aerobic and anaerobic bacteria per wound, often including Staphylococcus aureus, Pasteurella species, Bacteroides, Fusobacterium, Capnocytophaga, and Porphyromonas species. 4

• Prophylactic antimicrobials should be given as early as possible to all patients with cat scratches, particularly hand wounds, which are often more serious than wounds to fleshy parts of the body. 4

• Recommended regimen: Amoxicillin-clavulanate 875/125 mg twice daily for 3-5 days provides coverage against both aerobic and anaerobic organisms. 4

Follow-Up and Monitoring

• Elevate the affected hand using a sling and follow up within 24 hours either by phone or during an office visit. 4

• If infection progresses despite good antimicrobial therapy, hospitalization should be considered. 4

• Pain disproportionate to the severity of injury but located near a bone or joint should suggest periosteal penetration, which would necessitate prolonged therapy (4-6 weeks for osteomyelitis, 3-4 weeks for synovitis). 4

Summary Algorithm

1. Wound care: Soap and water for 15 minutes + povidone-iodine irrigation 1
2. Tetanus: None needed (last dose 2 months ago, <5 years for contaminated wound) 2
3. Rabies: 2 doses vaccine only (Day 0 and Day 3), NO HRIG 1, 3
4. Antibiotics: Amoxicillin-clavulanate 875/125 mg BID × 3-5 days 4
5. Follow-up: Within 24 hours 4