Botulinal antitoxin


Botulism is a paralyzing illness caused by the action of neurotoxins produced by Clostridium botulinum. One method of management is injection of an equine botulinal antitoxin.
 
Incidence
9% of injections (immediate manifestations: 5%, delayed manifestations: 4%).
 
Clinical manifestations
Anaphylactic shock (occurs even with small amounts of serum): 1.9% of cases;
 
Urticaria: 2.6% of cases.
 
Serum sickness (injections exceeding 40 ml): 3.7% of cases.
 
Generalized erythema, laryngeal edema: 0.7% of cases.
 
Diagnostic methods
Cutaneous testing
 
Intradermal skin tests may be positive in patients presenting anaphylactic shock. However, the false negative rate is high (50%) and this test does not rule out the possibility of generalized reactions.
 
Mechanisms
IgE-mediated hypersensitivity probably underlies anaphylactic manifestations, but IgE antibodies have never been demonstrated.
 
The role of immune complexes is likely in cases involving serum sickness.
 
Management
No effective prevention for immediate manifestations.
 
Inject less than 40 ml of botulinal antitoxin so as to minimize serum sickness.
 
Using botulinal immune globulin obtained from hyperimmunized human donors will be beneficial.

References

  1. Black RE, Gunn RA, "Hypersensitivity reactions associated with botulinal antitoxin", Am. J. Med., 1980; 69: 567–70

As in all diagnostic testing, the diagnosis is made by the physican based on both test results and the patient history.