Diphtheria hypersensitivity test
Adult: 0.1 ml of diphtheria antitoxin (equine) in 0.9% sodium chloride in a 1:100 dilution. Skin test read 20 minutes later. If patient has a history of allergy: 0.05 ml of a 1:1000 dilution. An inj of 0.9% sodium chloride can be used as a control. A positive reaction is represented by an urticarial wheal, with or without pseudopods, with a zone of erythema.
Intravenous
Mild to moderate nasal diphtheria
Adult: 10 000-20 000 units via slow IV infusion.
Intravenous
Mild to moderate tonsillar diphtheria
Adult: 15 000-25 000 units via slow IV infusion.
Intravenous
Laryngeal diphtheria, Pharyngeal diphtheria
Adult: 20 000-40 000 units via slow IV infusion.
Intravenous
Severe diphtheria
Adult: Up to 100 000 units by slow IV infusion.
Intravenous
Mild to moderate cutaneous diphtheria
Adult: Only used if ulcer >2 cm2 (insufficiently absorbed in smaller ulcers). Dose: 20 000-40 000 units by slow IV infusion.
Subconjunctival
Diphtheria hypersensitivity test
Adult: 1 drop of a 1:10 dilution of equine diphtheria antitoxin administered to lower conjunctival sac of 1 eye, control test of 0.9% sodium chloride administered to other eye. Test read after 15 minutes. A positive test is represented by ocular itching, burning, redness and lacrimation which can be relieved by applying 1 drop of ocular epinephrine solution on the affected eye.
Subcutaneous
Desensitisation of diphtheria hypersensitivity
Adult: Diphtheria antitoxin (equine) is administered in incremental doses every 15 minutes: 0.05 ml of a 1:20 dilution, 0.1 ml of 1:10 dilution, 0.3 ml of a 1:10 dilution and 0.1 ml of undiluted antitoxin. After another 15 minutes, 0.5 ml of undiluted antitoxin is administered IM or IV.
Topical/Cutaneous
Scratch skin test for diphtheria hypersensitivity
Adult: 1 drop of a 1:100 dilution of equine diphtheria antitoxin placed on the skin and then a 0.64 cm scratch made through the drop. A control of 0.9% sodium chloride can be used. Test read after 20 minutes. A positive reaction is represented by an urticarial wheal, with or without pseudopods, with a zone of erythema.