Q: Can an adult develop allergies? My sister suddenly can’t eat seafood.
A: Yes. People can develop allergies or allergic asthma at any age. It’s likely that some of them had an allergic reaction as a child or adolescent that they don’t remember. Moreover, if you have one allergy, you can progress to others over the years, perhaps as a result of getting a new pet or moving to a region with different trees, plants and grasses.
Most true food allergies begin in the first or second year of life, but they certainly can develop in adulthood, with seafood being the most common culprit. If you’ve never had trouble with seafood and suddenly get ill after eating it, you may not know whether it is an allergy or food poisoning. The reaction may worsen after a second exposure.
In addition, food intolerances (to lactose in milk, for example) are more likely to begin, or at least become more bothersome, in adulthood.