Consider food additives as allergens
Food additives, in the form of colorants, preservatives, or flavoring agents, can cause allergic reactions, Dr. Ehrlich noted.
The question of whether food-additive contact sensitivity has a role in the occurrence of atopic dermatitis (AD) in children remains unclear, she said. However, a study published in 2020 found that 62% of children with AD had positive patch test reactions to at least one food-additive allergen, compared with 20% of children without AD. The additives responsible for the most reactions were azorubine (24.4%); formic acid (15.6%); and carmine, cochineal red, and amaranth (13.3% for each).
Common colorant culprits in allergic reactions include carmine, annatto, tartrazine, and spices (such as paprika and saffron), Dr. Ehrlich said. Carmine is used in meat to prevent photo-oxidation and to preserve a red color, and it has other uses as well, she said. Carmine has been associated with ACD, AD flares, and immediate hypersensitivity. Annatto is used in foods, including processed foods, butter, and cheese, to provide a yellow color. It is also found in some lipsticks and has been associated with urticaria and angioedema, she noted.
Food preservatives that have been associated with allergic reactions include butylated hydroxyanisole and sulfites, Dr. Ehrlich said. Sulfites are used to prevent food from turning brown, and it may be present in dried fruit, fruit juice, molasses, pickled foods, vinegar, and wine.
Reports of ACD in response to sodium metabisulfite have been increasing, she noted. Other sulfite reactions may occur with exposure to other products, such as cosmetics, body washes, and swimming pool water, she said.
Awareness of allergens in supplements is important “because the number of our patients taking supplements for different reasons is increasing” and allergens in supplements could account for flares, Dr. Ehrlich said. Clinicians should encourage patients to tell them what supplements they use. Clinicians should review the ingredients in these supplements with their patients to identify potential allergens that may be causing reactions, she advised.
Dr. Ehrlich has disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.