Carrot-Induced Systemic Reaction: A Unique Presentation of Pollen-Food Allergy Syndrome in a Young Boy

Pollen-food allergy syndrome (PFAS) is a common IgE-mediated allergic condition resulting from cross-reactions between pollen and plant food allergens, primarily those in the PR-10 subfamily. Mostly symptoms are limited to the mouth and throat causing oral allergy syndrome (OAS). Systemic reactions are extremely rare. We report an 11-year-old boy who experienced a unique anaphylactic reaction after consuming raw carrot juice. The patient exhibited symptoms within one minute, including abdominal pain, facial and eyelid swelling, dyspnea, a macular rash, choking sensation and drowsiness. Desloratadine alleviated these symptoms, and as his overall condition improved rapidly, there was no need for adrenaline administration. Carrot-specific IgE levels in the patient's serum were as follows: Dau c: 40.63 kUA/L and Dau c1: 31.5 kUA/L. He had previously been diagnosed with seasonal allergic rhinoconjunctivitis. The high degree of similarity among allergen components within the PR-10 subfamily contributed to cross-reactivity between birch pollen and carrots. It is important to remember that PFAS can manifest systemically, with symptoms ranging from mild skin itching to potentially fatal consequences. This highlights the need for healthcare professionals to be extra cautious and aware of this possibility, especially since carrots are commonly found in a wide range of dishes and snacks.