What is the appropriate management of a cat‑scratch wound in an otherwise healthy adult, including wound cleaning, tetanus prophylaxis, and first‑line antibiotic therapy?

Management of Cat-Scratch Wounds in Healthy Adults

For an otherwise healthy adult with a cat-scratch wound, perform immediate thorough wound cleaning with copious irrigation, administer tetanus toxoid (Tdap preferred) if ≥5 years since last dose, and reserve antibiotics only for severe or complicated cases—most cat-scratch wounds do not require antimicrobial therapy. 1, 2

Immediate Wound Care

• Irrigate the wound copiously with soap and water for at least 15 minutes, then apply povidone-iodine solution if available. This mechanical decontamination markedly reduces infection risk and is as critical as any antimicrobial intervention. 2

• Do not perform primary closure of cat-scratch wounds except for facial lacerations. For facial wounds, use copious irrigation, cautious debridement, and preemptive antibiotics before closure. Other wounds may be approximated but not formally closed. 1

• Avoid closing puncture wounds or wounds of the hand, as these locations carry higher infection rates when closed. 1

Tetanus Prophylaxis Algorithm

Cat scratches are classified as contaminated, tetanus-prone wounds because they may be contaminated with dirt, soil, saliva, and feces—this classification determines a critical 5-year (not 10-year) interval for booster consideration. 2

For patients with ≥3 documented tetanus doses:

• If last dose was <5 years ago: No tetanus vaccination needed. 2

• If last dose was ≥5 years ago: Administer tetanus toxoid-containing vaccine (0.5 mL IM into deltoid) without TIG. Tdap is strongly preferred over Td if the patient has not previously received Tdap or Tdap history is unknown, as this provides additional pertussis protection. 1, 2

For patients with <3 documented doses or unknown vaccination history:

• Administer BOTH tetanus toxoid-containing vaccine (Tdap preferred) AND tetanus immune globulin (TIG) 250 units IM, using separate syringes at different anatomical sites. 2

• Initiate a complete 3-dose primary series: second dose ≥4 weeks after first, third dose 6-12 months after second. Do not restart if interrupted—simply continue from where the patient left off. 2

Special populations requiring TIG regardless of vaccination history:

• Severely immunocompromised patients (HIV infection, severe immunodeficiency) with cat-scratch wounds should receive TIG 250 units IM regardless of prior tetanus vaccination status. 2

Antibiotic Therapy Decision Algorithm

The majority of cat-scratch disease cases in immunocompetent hosts resolve spontaneously and do not require antibiotic therapy. 3, 4

Indications for antibiotic therapy:

• Severe systemic symptoms (persistent high fever, significant malaise, prolonged course) 4, 5
• Atypical presentations: hepatosplenic involvement, encephalopathy, endocarditis, osteomyelitis, Parinaud oculoglandular syndrome, stellate neuroretinitis 3, 4
• Immunocompromised patients (risk of bacillary angiomatosis, bacillary peliosis, relapsing bacteremia) 3
• Extensive lymphadenopathy causing significant discomfort or functional impairment 5

First-line antibiotic choices when treatment is indicated:

Azithromycin is the preferred first-line agent based on the only placebo-controlled trial showing more rapid diminution of infected lymph nodes. 3

Alternative effective agents (in descending order of efficacy based on clinical studies):

• Rifampin (87% efficacy) 5
• Ciprofloxacin (84% efficacy) 5
• Gentamicin IM (73% efficacy—reserve for severely ill patients) 4, 6, 5
• Trimethoprim-sulfamethoxazole (58% efficacy) 4, 5

Fourteen commonly prescribed antibiotics showed little or no clinical value in cat-scratch disease, including most penicillins and cephalosporins, despite in vitro susceptibility. 5

Critical Clinical Pitfalls to Avoid

• Do not confuse the 10-year routine booster interval with the 5-year interval required for contaminated wounds like cat scratches. This is the most common error in tetanus prophylaxis. 2

• Do not administer tetanus boosters more frequently than recommended, as this increases the risk of Arthus-type hypersensitivity reactions. 2

• Do not prescribe antibiotics routinely for simple cat-scratch disease in immunocompetent patients—conservative symptomatic treatment is recommended for mild to moderate cases. 5

• Do not assume adequate tetanus immunity based on age alone—38% of tetanus cases occur in patients ≥65 years, and only 21% of women >70 years have protective antibody levels. 7

• When administering both TIG and tetanus toxoid, always use separate syringes at different anatomical sites to prevent interference with the immune response. 2