IgE-mediated reactions
Oil palm pollen may commonly induce symptoms of allergic rhinitis and asthma in sensitised individuals, especially in Malaysia and Singapore (1-2).
In an aerobiologic survey of Singapore, crude extracts of 23 major spore (fungal and fern) and pollen types were assessed in 231 patients with asthma and/or allergic rhinitis and 76 healthy controls by skin prick test and total and specific IgE tests. Extracts of Oil palm pollen were observed to have the highest frequency of positive reactions (40%). Positive responses to these extracts correlated with total serum IgE levels of the subjects and were significantly associated with the presence of atopic disease (3).
A total of 107 patients with allergic rhinitis and/or asthma in Jakarta, Indonesia, were evaluated via skin prick test: 32 children and 75 adolescents and adults; there were also 20 normal control volunteers. Sensitisation to Palm oil pollen was demonstrated in 22.43%. No difference was noted between children and adults in the allergic group (4).
A study of the prevalence of allergen sensitisation among asthmatics in Thailand (84 paediatric, 71 adult asthmatics) found that sensitisation to Oil palm pollen in child and adult asthmatics was 8.3% and 5.6%, respectively (5).
Other reactions
Allergy to the fruit of Oil palm is possible. In a study that identified sensitivity to a Coconut (Cocos nucifera) 7S globulin in 2 Coconut-allergic patients, the greatest similarity was to a protein from Oil palm, a species also belonging to the Arecaceae family. Cross-reactivity among Coconut, Walnut, and Hazelnut was demonstrated by inhibition studies in patient 2 (6).