Prevalence of sensitization to food allergens and challenge proven food allergy in patients visiting allergy centers in Rawalpindi and Islamabad, Pakistan.

Muhammad Inam,Nabila Roohi,Muhammad Ismail,Muhammad Irfan,Shahid Abbas,Rubaba Hamid Shafique

doi:10.1186/s40064-016-2980-0

Abstract

In this study, we estimated the prevalence of food allergy in the adult allergic patients of Rawalpindi and Islamabad , Pakistan, based on self-report, skin prick test (SPT) and oral food challenge test (OFC). SPT was used for the estimation of sensitization to wheat, egg, milk, beef, chicken, mutton, fish, corn, lentils, rice, soya, peanut and banana. Among 689 patients, 39.19 % showed sensitivity to one or more foods, where, sensitization to wheat (156; 22.6 %) was highest, followed by egg (148; 21.48 %) and milk (138; 20.03 %). Sensitization to various proteins ranged between 15.53–15.97 %, while lentils, corn, rice, soya and peanut sensitization was 15.4, 16, 12.5, 12 and 11.5 % respectively. Only 7.1 % patients were SPT positive for banana allergen. SPT was performed in patients with self-reported food allergy (341/689) and also with no self-reported history of food allergy (348/689). SPT results were positive in 69.8 % of the self-report group, whereas, in the patients with no self-reported food allergy 9.2 % were found sensitized to one or more tested food allergens. 101 patients were recruited for OFC, 61 % of these were confirmed of food allergy. The prevalence of food allergy in the study population was 9 %. Food specific OFC results show that wheat allergy is affecting 1.6 % (95 % CI 0.9–2.84 %) of the total allergy patients, followed by egg allergy 1.31 % (95 % CI 0.70–2.47 %). Furthermore, corn allergy, rice allergy and peanut allergy were 1.02, 0.87 and 0.73 %, respectively. In conclusion, wheat allergy is the most prevalent, followed by egg, chicken, beef and fish allergy, respectively.

Highlights

Food allergy is a malfunction of the immune system in response to dietary antigens (Beyer and Teuber 2004)
Most of the studies focusing on milk allergen sensitization using Skin Prick Test (SPT), target various age groups of children
Worldwide SPT data are highly variable, 1 % milk sensitivity was reported from Turkish hospital (Kucukosmanoglu et al 2008), 1.1 % of random school children in Turkish population (Mustafayev et al 2013) and 0.1 % in the general population in Germany (Zuberbier et al 2004)

Summary

Introduction

Food allergy is a malfunction of the immune system in response to dietary antigens (Beyer and Teuber 2004). Food allergy develops in genetically predisposed individuals as a consequence of oral tolerance failure (Sampson 2004). Symptoms of food allergy are as diverse as in other allergies. There is no substantial scientific evidence, it is estimated that the prevalence of food allergy has increased over the past few decades (van Ree et al 2015), reaching 3–6 % (exceeding 10 % in some regions), significantly influencing the quality of life and adding to the economic burden of a society (Hadley 2006). Changing dietary habits and availability of all kinds of food products around the world may be a cause of the increase in food allergies. An increase in the prevalence of some food

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Conclusion