Hazelnuts and OAS: Testing with allergen components helps aid in dietary management of hazelnut allergic patients
Manuel, an 18-year-old with a history of rhino-conjunctivitis, visit his healthcare provider after developing oral symptoms, throat thickening, and urticaria after eating a piece of cake containing hazelnuts.
Manuel's healthcare provider conducts a full clinical history and physical examination and decides to test using components.
A boy with a history of rhino-conjunctivitis develops oral symptoms and urticaria after eating a piece of cake.
Patient History
Family History
- Atopic mother.
Manuel's Personal History
- Rhino-conjunctivitis during the summer since 7 years of age.
- Oral itching when eating peach.
| Test | Type | Manuel's Results |
| Olive pollen | Whole Allergen | +5 |
| Peach | Whole Allergen | +3 |
Manuel had a negative skin prick test to grass, mugwort, dog, cat, and mite.
| Test | Type | Manuel's Results |
| Olive pollen | Whole Allergen | 28.5 |
| Peach | Whole Allergen |
8.1 |
Based on history, evaluation, and testing their previous healthcare provider recommended that Manuel use antihistamines during spring/summer and to avoid peaches.
Manuel's ImmunoCAP Test Results
These results together with this patient's case history and symptoms, help confirm the diagnosis.
| Test | Type | Manuel's Results |
| Olive | Whole Allergen | 35.4 |
| Peach | Whole Allergen | 12.9 |
| Hazelnut | Whole Allergen | 3.1 |
| Cor a 1 | Allergen Component | <0.1 |
| Cor a 8 | Allergen Component | 3.5 |
| Cor a 9 | Allergen Component | <0.1 |
| Cor a 14 | Allergen Component | <0.1 |
| Pru p 3 | Allergen Component | 11.5 |
| Ole e 1 | Allergen Component | <0.1 |
| Ole e 7 | Allergen Component | 21.2 |
| Ole e 9 | Allergen Component | 2.7 |
Differential Diagnosis
The presence of IgE antibodies to Cor a 8 confirms that Manuel’s hazelnut allergy is lipid transfer protein (LTP) dependent. He has no detectable IgE antibodies to storage proteins, but his LTP-dependent sensitization to hazelnut shows that he runs a risk of even more severe reactions than urticaria. He may experience reactions to other nuts and fruits that contain LTP, e.g., walnuts and apples.1,2
REFINED DIAGNOSIS
- LTP-dependent peach and hazelnut allergy and olive pollen allergy.
HEALTHCARE PROVIDER MANAGEMENT PLAN
- Manuel's healthcare provider advises him to strictly avoid peaches and hazelnuts.
- Manuel's healthcare provider also advises him to be cautious with other LTP-containing nuts and fruits, e.g., walnuts and apples.
- Manuel's healthcare provider arranges a follow-up education and training emergency adrenaline autoinjector use for Manuel.
FOLLOW UP
- Manuel is seen by his healthcare provider one year later. He has had no further episodes, and is fit and well. His healthcare provider checks his autoinjector technique and is satisfied.
The people, places, and events depicted in these case studies and photographs do not represent actual patients, nor are they affiliated in any way with Thermo Fisher Scientific.
- Hartz C, et al. Comparison of IgE-binding capacity, cross-reactivity and biological potency of allergenic non-specific lipid transfer proteins from peach, cherry and hazelnut. Int Arch Allergy Immunol. 2010;153:335-46
- García BE, Lizaso MT. Cross-reactivity syndromes in food allergy. J Investig Allergol Clin Immunol2011;21:162–170.
