Rare immediate hypersensitivity to rifampicin in a patient with tuberculosis requiring drug discontinuation

A 47-year-old Turkish female patient was diagnosed with tuberculosis of the sacro-iliac joints and terminal ileum. She developed a severe adverse drug reaction while taking first-line tuberculosis therapy consisting of isoniazid, pyrazinamide and rifampicin as Rifater and ethambutol. Within 5 min of ingestion she developed pruritic rash, angioedema and breathing difficulties, resulting in an A&E admission. The tuberculosis therapy was discontinued. Intradermal and oral challenge tests for rifampicin were conducted but abandoned early on due to reactions which included audible wheeze, vomiting, throat pain and violent rigours. Clinical manifestations were swiftly treated with appropriate medications. This resulted in a change to the tuberculosis treatment regime, where streptomycin, isoniazid, ethambutol and pyrazinamide were given for 2 months and isoniazid and ethambutol for 12 months. Allergic reactions to rifampicin are rare and should be distinguished from flushing due to pyrazinamide. Prompt diagnosis and treatment by clinicians can be life saving.