Anaphylaxis to quinolones in mastocytosis: Hypothesis on the mechanism

Genetic study for KIT mutation was not done. [...]SM without cutaneous involvement was diagnosed. [...]the frequency of clonal mast-cell disease in screened subjects with HVA ranges from 1% to 7.9%.4,5 The risk of anaphylaxis in mastocytosis increases with higher levels of tryptase. [...]more severe Hymenoptera HSRs are also associated with higher baseline serum tryptase levels in patients without SM.4,5 Our patient had an abnormal serum tryptase level (17.7 μg/L). [...]the diagnosis is challenging, because drug-specific sIgE tests are unavailable and skin testing presents undetermined sensitivity and specificity.3 Quinolones are one of the substances that may activate mast cells through MRGPRX2, resulting in non–IgE-mediated release of mediators, as described above.7 In conclusion, the excess of mast cells and their MRGPRX2 receptors in patients with mastocytosis may induce anaphylaxis on activation by quinolones.