Desensitization to co-trimoxazole (trimethoprim-sulphamethoxazole) in HIV-infected patients: is patch testing a useful predictor of reaction?
OBJECTIVE
To establish the safety and efficacy of desensitization to co-trimoxazole in hypersensitive HIV-infected subjects. To assess if delayed hypersensitivity (type IV) to co-trimoxazole predicts those unable to be desensitized.


METHODS
desensitization to co-trimoxazole, comprising trimethoprim (T) 0.4 mg and sulphamethoxazole (S) 2 mg initially with doubling dose daily, full strength co-trimoxazole (T/S 160 mg/800 mg) at 10 days. Patch testing with 4.5% and 9% co-trimoxazole in yellow soft paraffin, CMI Multitest.


RESULTS
nineteen patients, 18 male and one female, were recruited and completed the desensitization regime. Of these 80%(15) achieved successful desensitization. Three of those who reacted did so within 18 days. All patients were successfully managed in an outpatient setting. There were no major adverse reactions. Of those reacting none gave a positive patch test to co-trimoxazole and all showed absent delayed type hypersensitivity reactions to recall antigens.


CONCLUSIONS
co-trimoxazole desensitization is a safe and efficacious procedure, with a success rate of 80% using the above regime. Patch testing with co-trimoxazole gives no useful information about those that reacted.
Gompels
M M
MM
Department of Immunology, Southmead Hospital, Bristol, UK.
Simpson
N
N
Snow
M
M
Spickett
G
G
Ong
E
E
D000328:Adult; D000890:Anti-Infective Agents / Q000276:immunology* / Q000627:therapeutic use; D003888:Desensitization, Immunologic; D004342:Drug Hypersensitivity / Q000517:prevention & control*; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000188:drug therapy / Q000276:immunology*; D006801:Humans; D006968:Hypersensitivity, Delayed; D008297:Male; D010045:Outpatients; D010328:Patch Tests; D011020:Pneumonia, Pneumocystis / Q000150:complications / Q000188:drug therapy / Q000517:prevention & control*; D011237:Predictive Value of Tests; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000276:immunology* / Q000627:therapeutic use
D000890:Anti-Infective Agents; D015662:Trimethoprim, Sulfamethoxazole Drug Combination