Children suffering from diseases like gastroesophageal reflux disease are usually prescribed with proton pump inhibitors. It is done so as to significantly eradicate and eliminate all the helicobacter and also help to prevent steroid associated drugs or anti inflammatory drugs. Majority of the PPI HRs are IgE‐mediated. There may be a delay in release formulation of polymorphisms in the cytochrome P450 CYP2C19 gene which thereby leads to slow the drug’s metabolism. Usually sensitization to PPIs takes place by oral, or by intravenous, or through skin routes. As per the database PPIs triggered 0.8% of anaphylaxis. PPIs elicited anaphylactic reactions in approximately 14 patients and it elicited the urticaria‐angioedema in 6 patients. Based on the local habits of PPI prescriptions relative frequency of PPI involvement varies. As a  conclusion we can say that through the various studies it is evident that There are three possible patterns of cross‐reactivity of PPIs. Which means patients who show hypersensitivity to a single PPI and at the same time react to all other PPIs is only because of the involvement of 2‐pyridyl‐methyl‐sulfinyl‐benzimidazole nucleus in rest of the PPIs. There are patients who have allergy to a single PPI and tolerance to all the other PPIs.

Reference link – https://onlinelibrary.wiley.com/doi/10.1111/pai.13345