Is equine-based rabies serum (Equine Rabies Immune Globulin) applied to the shaft of the penis after a potential rabies exposure?

Rabies Immunoglobulin Administration for Penile Exposures

Equine rabies immune globulin should NOT be applied to the shaft of the penis; instead, it should be thoroughly infiltrated around and into the wound site only, with any remaining volume injected intramuscularly at a site distant from vaccine administration.

Proper Administration of Rabies Immunoglobulin

• For post-exposure prophylaxis, rabies immunoglobulin (whether human or equine) should be infiltrated thoroughly in the area around and into the wounds, if anatomically feasible 1, 2
• Any remaining volume should be injected intramuscularly at a site distant from vaccine administration 1, 2
• The recommended dose is 20 IU/kg body weight for both human and equine rabies immunoglobulin 1, 2
• This administration technique is critical as rare failures of post-exposure prophylaxis have occurred when smaller amounts of rabies immunoglobulin were infiltrated at exposure sites 1, 2

Specific Considerations for Penile Exposures

• For penile wounds, the same principles apply - the immunoglobulin should be infiltrated around and into the actual wound site only, not applied generally to the shaft of the penis 1
• Proper wound cleansing with soap and water and a virucidal agent is an essential first step before immunoglobulin administration 2
• The full dose should never be applied indiscriminately to anatomical areas not directly involved in the exposure 1

Important Precautions

• Rabies immunoglobulin should never be administered in the same syringe or at the same anatomical site as the vaccine 1, 2
• Equine rabies immunoglobulin (ERIG) carries a higher risk of adverse reactions compared to human rabies immunoglobulin (HRIG) 1
• Potential adverse reactions to ERIG include:
  • Serum sickness (fever, rash, arthralgia) occurring approximately 7-10 days after administration 3, 4
  • Anaphylaxis, though rare with modern purified preparations 5
  • Local pain and low-grade fever 1

Administration Timeline

• Rabies immunoglobulin should be administered only once at the beginning of post-exposure prophylaxis 1, 2
• If not given when vaccination was begun, it can still be administered through the seventh day after the first vaccine dose 1, 2
• Beyond the seventh day, rabies immunoglobulin is not indicated as an antibody response to the vaccine is presumed to have occurred 1, 2

Clinical Pearls and Pitfalls

• A common pitfall is applying immunoglobulin to unaffected areas rather than concentrating it at the wound site 1
• Failures in post-exposure prophylaxis have occurred when:
  • Wounds were not properly cleansed 1
  • Insufficient amounts of rabies immunoglobulin were infiltrated at the exposure sites 1
  • Vaccine was administered in inappropriate anatomical sites (e.g., gluteal area instead of deltoid) 1
• In developing countries where HRIG might not be available, purified ERIG has been used effectively with a relatively low incidence of adverse reactions (0.8%-6.0%) 1, 6