Peanut allergy (PA) has become a major health concern, but the reasons for this increasing prevalence are not well understood.1 Although the consumption levels of peanuts in the USA and China are similar, the rate of PA was believed to be much lower in China.1 Hong Kong is one of the most Westernised city of China, and the prevalence in atopic disorders such as asthma, allergic rhinitis and atopic eczema were comparable with most developed countries; yet PA was rarely encountered in the past decades until recently. A recent study showed a prevalence of PA of 0.52%–0.65% in preschoolers.2 We speculate that this could be related to changes in diet and culture over the past decades. …