No Skin Test Required for Tetanus Prophylaxis
Skin testing should NOT be performed before administering tetanus toxoid or tetanus immunoglobulin (TIG). The FDA explicitly states that "skin tests should not be done" because intradermal injection of concentrated IgG solutions causes localized inflammation that can be misinterpreted as an allergic reaction, when it actually represents tissue irritation rather than true allergy 1. This misinterpretation can lead physicians to inappropriately withhold needed human antitoxin from patients who are not actually allergic 1.
Why Skin Testing Is Contraindicated
- Skin tests create false-positive results through localized tissue irritation from concentrated immunoglobulin, not true allergic responses 1
- True allergic reactions to human immunoglobulin are rare when given via the prescribed intramuscular route 1
- Withholding treatment based on false-positive skin tests puts patients at risk for preventable tetanus infection 1
Proper Approach for Unknown Vaccination History with Contaminated Wounds
For patients with unknown or incomplete vaccination history (<3 documented doses) presenting with potentially contaminated wounds, immediately administer BOTH tetanus toxoid-containing vaccine (Tdap preferred) AND TIG 250 units IM at separate anatomical sites using separate syringes 2, 3, 1.
Vaccination Algorithm
- Unknown or <3 doses + contaminated wound: Give Tdap AND TIG 250 units IM at different sites 2, 3, 1
- Unknown or <3 doses + clean, minor wound: Give Tdap only, no TIG needed 2, 3, 1
- ≥3 documented doses + contaminated wound + last dose ≥5 years ago: Give Tdap only, no TIG needed 2, 3
- ≥3 documented doses + contaminated wound + last dose <5 years ago: No vaccination or TIG needed 2
Critical Administration Details
- Use separate syringes at different anatomical sites when giving both TIG and tetanus toxoid to prevent interference with immune response 3, 4, 1
- Tdap is strongly preferred over Td for persons ≥11 years who have not previously received Tdap or whose Tdap history is unknown 2, 3, 4
- Treat unknown vaccination history as zero previous doses - patients with uncertain histories should be considered to have had no previous tetanus toxoid 3, 1
Safety Considerations
- Epinephrine should be available for treatment of acute anaphylactic reactions, though systemic reactions to human immunoglobulin preparations are rare 1
- Never administer TIG intravenously - it is intended for intramuscular use only and IV injection can cause precipitous blood pressure drops 1
- Avoid the gluteal region for injection due to risk of sciatic nerve injury; use deltoid or lateral thigh muscle instead 1
Common Clinical Pitfalls
- Do not perform skin testing - this is explicitly contraindicated and leads to inappropriate withholding of needed prophylaxis 1
- 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
- Do not assume military service equals complete vaccination - while persons with military service since 1941 likely received at least one dose, completion of the primary series cannot be assumed 1