Anaphylactic reaction to ambroxol

Ambroxol is a commonly used mucolytic agent for respiratory tract infections; however, immediate hypersensitivity reactions are rarely reported in children. We describe a 13-year-old male with allergic rhinitis and atopic dermatitis who developed generalized urticaria, angioedema, dyspnea, and syncope shortly after receiving loratadine–ambroxol prescribed for an upper respiratory infection. Skin testing with amoxicillin, azithromycin, paracetamol, and ambroxol yielded negative results. Drug provocation testing (DPT) was subsequently performed, showing negative responses to amoxicillin, azithromycin, and paracetamol. During the ambroxol challenge (3–27 mg), the patient developed rhinorrhea, sneezing, ocular and nasal pruritus, followed by dyspnea, wheezing, bilateral eyelid angioedema, generalized urticaria, oxygen desaturation, tachycardia, and hypotension—findings consistent with grade III anaphylaxis according to the Brown classification. He required two intramuscular doses of epinephrine, with complete clinical recovery. Ambroxol was permanently contraindicated, and an epinephrine autoinjector was prescribed. This case reinforces that severe ambroxol-induced hypersensitivity can occur despite negative skin testing, highlighting the value of DPT. Given the widespread use of ambroxol and its potential to trigger life-threatening reactions, clinicians should prioritize rational prescribing in upper respiratory infections and report severe adverse events to pharmacovigilance systems. This case adds to the limited pediatric evidence confirming ambroxol-induced anaphylaxis through controlled drug exposure.