Clinical Experience
IgE-mediated reactions
Nettle pollen frequently induces asthma, allergic rhinitis and allergic conjunctivitis. (5)
Allergen-specific IgE to Urtica has also been detected due to occupational sensitisation. (6)
Urticaceae pollen including both Parietaria and Urtica has been detected in large quantities in aeroallergen studies. It is reported to be the predominant pollen in northwest Spain. (7) In Muros, Spain, pollen from this plant comprised 67% of the total aeroallergen load. The proportion of Urticaceae pollen found in Muros was the highest among all samples belonging to the Spanish Aerobiology Network. (8) Other studies from Salamanca, Cordoba (9), and other parts of Spain (10, 11, 12) have documented the importance of this aeroallergen in this country. Urticaceae pollen has also been reported in Italy (13), Poland (14) and Switzerland. (15)
Nettle pollen is also an important aeroallergen in England. IgE antibodies to Nettle pollen was found in 13 of 62 patients with a clinical history of summer seasonal respiratory symptoms. (16)
Nettle pollen has also been detected in aeroallergen studies in Rochester, New York, Minnesota, (17) Nebraska, (18) and Texas, (19) in Balikesir, Turkey, (20) and in Korea. (21)
Other reactions
Stinging Nettle can cause a wide range of cutaneous reactions (22), including Stinging Nettle-induced urticaria (23) and contact urticaria (24) following non-pollen contact with the Nettle plant. Immediate and delayed hypersensitivity reactions to the Nettle plant may also occur. (25)
A 57-year-old woman showed symptoms of atropine poisoning after drinking Stinging Nettle tea. Belladonna (Atropa belladonna) was found on investigation to be present in the tea. (26)