Summary

Sweet chestnut, a member of the Fagaceae family, is commonly consumed raw or roasted due to its rich nutritional value. Allergy to chestnuts has been widely reported in latex-fruit syndrome, whereas reports of primary chestnut food allergy are rare. The main chestnut allergens that have been identified include Cas s 5, Cas s 8 and Cas s 9.

Epidemiology

Worldwide distribution

In Korea, fresh and boiled chestnuts are commonly eaten and account for the third most prevalent food allergen and most prevalent tree nut allergen in pediatric and adult allergy patients. In one study, the sensitization rate to homemade chestnut extract was 3.2% in Korean self-described adult allergy patients.

Clinical Relevance

Allergy to chestnuts has been widely reported in latex-fruit syndrome although reports of primary chestnut food allergy are extremely rare. Despite high sensitization rates to chestnut, indications about primary allergy to chestnut is through case studies. Out of 22 chestnut-allergic patients (including both primary allergic and cross-reactive patients with latex-fruit syndrome) 8 had experienced severe anaphylactic episodes upon chestnut ingestion.

Approximately 40–50 % of patients with latex allergy show hypersensitivity to freshly consumed fruits or nuts, mainly avocado, banana, chestnut, and kiwi, clinically referred to as latex-fruit syndrome. Chestnut accounts for around 24% of cases linked to this syndrome, after banana (28%) and avocado (28%).

One case of oral allergy syndrome has been reported in which chestnut was the causative food allergen.

Cross-Reactivity

Latex-fruit syndrome is a cross-reactive condition where primary sensitized patients to latex react to fruits or nuts including chestnuts. Allergy to latex usually precedes food allergy, although this is not always the case. In latex-fruit syndrome, symptoms are often severe after ingestion of these foods.

A study in patients with primary chestnut allergy (with no latex allergy) were sensitized to mugwort pollen (Cas s 8 reactivity to Art v 3) and peach (Cas s 8 reactivity to Pru p 3).