# Allergen Component Testing: Key in Diagnosing Atypical Pollen-Food Allergy Syndrome

## TL;DR

This case report highlights the use of allergen component testing to diagnose and manage a teenager with atypical pollen-food allergy syndrome.

## Contribution

The paper emphasizes the role of allergen component testing in identifying atypical cases of pollen-food allergy syndrome.

## Key findings

- Allergen component testing revealed cross-reactivity between Bet v 1 and hazelnut allergens in the patient.
- The patient showed improvement in symptoms after dietary advice and allergen avoidance.
- Collaboration and patient education are essential for effective long-term management of PFAS.

## Abstract

This case report details the complex presentation, diagnosis, and management of a teenager with pollen-food allergen syndrome (PFAS), formerly known as oral allergy syndrome. PFAS, mediated by immunoglobulin E (IgE) antibodies, stems from the cross-reactivity between pollens and uncooked plant-based foods, leading to a spectrum of symptoms, such as itching or tingling of the oral cavity. A UK survey indicated an average PFAS prevalence of 2%, with apples, hazelnuts, and kiwifruit commonly implicated. The presented case involved a 15-year-old girl referred from the respiratory clinic to the allergy clinic due to episodes of sore throat and urticaria rash following Nutella (chocolate paste containing hazelnut) and peanut consumption. Extensive diagnostic measures, including specific IgE testing, skin prick tests, and allergen component testing, revealed cross-reactivity between Bet v 1 and hazelnut allergens. The patient's atopic history, encompassing poorly controlled asthma, allergic rhinitis, and eczema, added layers of complexity to the diagnosis. Management strategies comprised dietary advice, allergen avoidance, and potential consideration of aeroallergen immunotherapy. A comprehensive dietary plan emphasized abstaining from specific foods and raising awareness of potential reactions. The patient, following guidance from the allergy clinic, exhibited improvements in allergic rhinitis and oral symptoms. This case underscores the importance of allergen component testing in diagnosing atypical PFAS presentations and tailoring management plans. Ongoing collaboration between healthcare providers, detailed patient education, and regular follow-ups are crucial for effective PFAS management and long-term care.