Exposure to quarternary ammonium ions via Pholcodine cough mixture coupled with laboratory evidence of potentiation of IgE antibody responses to NMB and marked epidemiological differences in the frequency of NMB anaphylaxis between Sweden (very low rate of NMB anaphylaxis) and Norway (high rate of NMB anaphylaxis), led Norway to ban pholcodine in 2007 (18). Here, IGHE is linked to anaphylaxis.