Hi Welcome to the HCM In my opinion your child seems to have had an allergic reaction to some allergens in the store. It might be an aeroallergen. Since allergic reactions can recur, so it s important to be careful and try to identify and then avoid the things from which your child is allergic. Where possible, breast feed your child for at least 6 months. Breastfeeding provides a nutritious and balanced food source for your baby, reduces the risk of gastrointestinal tract infections and may also reduce the risk of developing allergic disease in early life. Delay the introduction of solid foods until the child is 4-6 months of age. Thereafter, foods can be introduced, with a new food introduced every 2-3 days. Introduce one new food at a time so that any reactions can be readily identified. If he suffers again, try using anti histamines. If it doesn t respond, do go for your clinician advice after a proper examination. In case of further questions, do call back