Why does my mouth itch when eating fresh apples, but not with applesauce?

Question: Why does my mouth itch when eating fresh apples, but not with applesauce?

Answer: These symptoms are most likely due to something known as an oral allergy syndrome, caused by apples. The oral allergy syndrome (OAS) is a form of food allergy that is caused by a person having an allergy to a particular pollen. The pollen, in this case birch pollen, has similar proteins found in a certain fruit, in this case apple, which causes a person to be allergic to both.

When a fresh apple is eaten, a person may experience itching, burning, or stinging sensations of the mouth, throat and tongue. The symptoms generally last only a few seconds or minutes, as the proteins that cause the symptoms are broken down quickly by saliva. Since cooking, baking or processing the food (as is the case with applesauce) breaks down these proteins as well, a person with OAS to a fresh apple can eat applesauce without symptoms.

Want to find out more? Read the full-length article on the oral allergy syndrome.

Sources:

1. Sicherer SH. Clinical Implications of Cross-Reactive Food Allergens. J Allergy Clin Immunol. 2001; 108:881-90.

2. Ortolani C, Ispano M, Pastorella EA, Ansaloni R, Magri GC. Comparison of Results of Skin Prick Tests and RAST in 100 Patients with Oral Allergy Syndrome. J Allergy Clin Immunol. 1989; 83:683-90.

3. Sampson HA. Adverse Reactions to Foods. In: Adkinson NF, Yunginger JW, Busse WW, et al, eds. Middleton’s Allergy Principles and Practice. 6th edition. Philadelphia: Mosby Publishing; 2003:1619-1643.

DISCLAIMER: The information contained in this site is for educational purposes only, and should not be used as a substitute for personal care by a licensed physician. Please see your physician for diagnosis and treatment of any concerning symptoms or medical condition.