1-INTRODUCTION
Proton pump inhibitors (PPIs) belong to a group of chemically related
compounds whose primary function is the inhibition of acid production by
blocking the hydrogen potassium adenosine triphosphatase enzyme system
(H+/K+-ATPase).1,2 In adults and pediatric population,
these drugs are widely used for the treatment of peptic conditions, such
as gastric ulcers, gastroesophageal reflux disease, Helicobacter
pylori infections, eosinophilic esophagitis, as well as used to prevent
gastric damages due to prolonged use of corticosteroids and nonsteroidal
anti-inflammatory drugs (NSAIDs).3,4 They are usually
well-tolerated leading to over-prescription and consumption, with a risk
of side effects of approximately 1–3%.5 Given the
population-based PPI consumption ranging from 8% or 11% in the 20-24
aged males or females, to 34 – 41% in the 65 – 69 aged males or
females,6 , the risk for allergic side effects is
substantial. Observational studies have suggested an association between
PPI intake and risk of pneumonia, osteoporosis, enteric infection,Clostridium difficile –associated diarrhoea, cerebrovascular
events, chronic renal failure, dementia, and all-cause mortality,
especially in long-term usage.7,8 Their long term
intake has been facilitated by over-the-counter sales in most countries
and connects them with de novo induction of Th2 responses to food and
environmental allergens, in experimental, clinical and population based
epidemiologic studies. Their mechanisms of promoting Th2 immunity and
dysbiosis have been revealed in detail.6 Still,in
addition to their well-known risk profile, PPIs can induce immediate and
delayed hypersensitivity reactions (HSRs).9 The
optimal management of patients with HSRs to PPIs is still a matter of
discussion. This Position Paper, aims to provide clinicians with
practical evidence-based recommendations for the diagnosis and
management of HSRs to PPIs along with unmet needs in this area.