[Manifestations of rifampicin-induced hypersensitivity]

The side effects of rifampicine due to an immunoallergic mechanism are rare and usually observed during discontinued treatment or administration of high doses.

An immediate hypersensitivity reaction with anaphylactic manifestations and increase in IgE occurred in a 39 year-old man suffering from resistant tuberculosis. The reaction occurred within the first hour following a low dose of rifampicin administered in a desensitisation attempt, the outcome of which was favourable after administration of corticosteroids and antihistamines. A type II hypersensitivity reaction occurred in a 76 year-old male patient in the form of thrombopenia on D76 of a twice weekly treatment, diagnosed because of hemoptysis with normalisation of platelet level on withdrawal of rifampicin. An immune complex hypersensitivity reaction was responsible for hepato-renal failure on D68 of twice weekly treatment and required permanent withdrawal of rifampicin and dialysis, which led to subsequent improvement.

These clinical cases illustrate the variability of the hypersensitivity mechanisms observed with rifampicin, the difficulty in imputability tests and methods for immunological confirmation, the interest of continuous treatment which avoids a certain number of these accidents, and that of desensitisation during immediate hypersensitive reactions which permits the continuation this major anti-tuberculosis drug.