Allergies To Sulphonamides
Description General and Supportive Measures Medicine Treatment Referral ICD-10 code: Z88.2 DESCRIPTION The commonest sulphonamide allergies are related to co-trimoxazole, especially when used in HIV-infected patients for P. jirovecii treatment and/or prophylaxis. Patients may present with: a morbilliform or maculopapular rash only, usually within a few days of starting treatment (most commo
General and Supportive Measures
ICD-10 code: Z88.2
DESCRIPTION
The commonest sulphonamide allergies are related to co-trimoxazole, especially when used in HIV-infected patients for P. jirovecii treatment and/or prophylaxis.
Patients may present with:
- a morbilliform or maculopapular rash only, usually within a few days of starting treatment (most common presentation),
- a rash with fever, which may progress to,
- a drug-induced rash with eosinophilia and systemic symptoms (DRESS) usually with hepatitis (usually within 1 - 2 weeks of treatment commencement),
- SJS/TEN, or
- an immediate hypersensitivity reaction (rare).
GENERAL AND SUPPORTIVE MEASURES
Stop the sulphonamide-containing drug. Severe cutaneous drug reactions with or without organ involvement require admission and specialist review to optimise supportive management. See Stevens-Johnson syndrome (SJS)/Toxic epidermal necrosis (TEN).
MEDICINE TREATMENT
Options for HIV-infected patients requiring treatment for P. jirovecii pneumonia with a history of a mild reaction, e.g. rash to prior co-trimoxazole exposure.
P. jirovecii pneumonia treatment:
- There is no clear alternative recommendation to co-trimoxazole in this setting and thus a general alternative recommendation cannot be made. In these cases, management will need to be carefully considered with a specialist.
P. jirovecii pneumonia prophylaxis:
- Dapsone, oral, 2 mg/kg daily.
- Maximum dose: 100 mg (1 tablet) daily.
- Note: Dapsone is a sulphone, not a sulphonamide; but there are cases of cross-reactivity with sulphonamide allergy, however, reactions are usually mild. Avoid dapsone if there is a history of anaphylaxis, SJS/TEN, or rash with systemic involvement.
| If no alternative antibiotic is available, consider desensitisation after consultation with a specialist. Desensitisation to be done by a specialist in a tertiary facility. |
REFERRAL
- In cases where desensitisation is considered. Consult a specialist.
- For alternative antibiotics in all patients with severe immediate reactions.
Standard Treatment Guidelines and Essential Medicines List for South Africa, Hospital Level, Paediatrics, 2023 Edition
Chapter 25: Drug Allergies, 24.4 Specific Allergies, 24.4.2 Allergies To Sulphonamides