Q: As a baby, my son was diagnosed with a cow’s milk allergy and now, at age 4, had a reaction to cashews and the allergist has diagnosed him with a nut allergy. Is this type of food allergy progression common? might he gain more allergies?
Dr. Sicherer: About 35 percent of infants with a milk allergy go on to have other food allergies.
There is not a specific relationship with milk to other food allergens, but a person with a food allergy is, in general, prone to allergic problems including allergies to other foods, asthma, hay fever and atopic dermatitis (eczema).
For a person who is prone to food allergies, the main culprits are the classic “major” food allergens: peanuts, tree nuts, milk, eggs, shellfish, fish, wheat and soy.
It is possible for anyone to develop a new allergy. However it’s unusual to develop a new allergy to a food that is already a routine part of the diet. Most allergists would not suggest avoiding foods only based on their infamy as an allergen.
Decisions about avoiding specific foods should be discussed with your allergist.
Some of the considerations in deciding what to eat or avoid include the current diet, test results, known allergies, food relationship (for example cashew and pistachio are related), concern for cross-contact (for example among nuts), personal dietary preferences (in your case, which nuts to avoid) and other factors.
Dr. Scott Sicherer is Chief of the Division of Allergy and Immunology of the Jaffe Food Allergy Institute at the Icahn School of Medicine at Mount Sinai in New York. Together with Dr. Hemant Sharma of Children’s National Medical Center in Washington, he writes “The Food Allergy Experts” column in the American Edition of Allergic Living magazine. Questions submitted below will be considered for answer in the magazine.