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  Substance Info: (and synonyms)
Maize pollen / Corn pollen

Background Info:

Panicoideae

Pollen from the maize plant, as opposed to the allergen from the Maize grain.
See also Maize/Corn.

The original habitat is obscure; it was probably South America or Mexico. The plant is now grown anywhere in the world where summers are reasonably warm. Corn is one of the most commonly grown foods. It is the staple cereal of the human diet in Central and tropical South America and in many parts of Africa. It is extremely important in livestock rearing, food processing and other industrial activity in developed countries.

The plant is a single-stemmed annual, grown from one seed, though sucker shoots (which may produce seed) rise from the base. The single stalk, terminating in the tassel or staminate flowers, can grow to over 3m at a fast rate. The smooth leaves, usually drooping, usually green, can be over half a metre long.

The flowers are monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and are pollinated by wind. The female flowers are borne on a receptacle, termed -ear,- which arises at a leaf axil near the mid-point along the stem. Normally 1 to 3 or more such ears develop. The flower organs, and later the grain kernels, in more or less longitudinal rows, are enclosed in several layers of papery tissue, termed husks. Strands of "silk", actually the stigmas from the flowers, emerge from the terminals of the ears and husks at the same time the pollen from the terminal tassels is shed. It is in flower between July and October, and the seeds ripen between September and October. The grains are variable as to size, shape, and colour.

Sweet corn is distinguished from field corn by the high sugar content of the kernels at the early "dough" stage, and by wrinkled, translucent kernels when dry.

 

Adverse Reactions:

IMMUNE REACTIONS


[ 1 / 2 ]

Thirty-three Navajo patients were seen in an allergy consultation in Flagstaff, Arizona between 1978 and 1990. Sufficient skin test and historical data were available from nine atopic patients to evaluate hypersensitivity reactions to oral corn pollen used in the Navajo ceremonials. Six of the nine patients had positive skin test reactions to corn pollen and four of these six reported symptoms from oral corn pollen. The symptoms included various combinations of oral and ear itching, sneezing, cough, and wheezing. One corn pollen skin test-negative patient reported slight throat itching from the pollen. (Freeman 1994 ref.5632 7)

Reference:
Freeman GL. Oral corn pollen hypersensitivity in Arizona Native Americans: some sociologic aspects of allergy practice. Ann Allergy 1994;72(5):415-7



[ 2 / 2 ]

Forty patients with a well-documented history of seasonal hay fever and a positive skin-prick test specific to grass pollen, including Bermuda grass and maize pollen (Zea maize), received either an oral mixed grass-maize pollen extract or a matched placebo during the 1981/1982 grass pollen season. During the first year the patients on active therapy had significantly fewer hay fever symptoms during the summer months compared with the placebo group. During the second study year, with all patients on active therapy, both groups had markedly milder symptoms compared with the placebo group. Many patients with pollinosis showed positive skin prick tests to maize pollen and not to grasses, while others had positive tests to grass pollens but not to maize pollen. (Van Niekerk 1987 ref.2843 7)

Reference:
Van Niekerk CH, De Wet JI. Efficacy of grass-maize pollen oral immunotherapy in patients with seasonal hay-fever: a double-blind study. Clin Allergy 1987;17(6):507-13




Occupational reactions


[ 1 ]

Although maize pollen (MP) is abundantly produced, it is found in low concentrations as an airborne pollen because of its weight. In fact, most MP will fall within 50-70 m from the source. So, it has been widely assumed to be a minor agent of pollinosis. This case report was of a 55-year-old man with a 16-year history of recurrent episodes of rhinoconjunctivitis and asthma from July to September. He worked in a rural area where maize, fruit trees and vegetables are found in abundance. Prick tests were negative for a number of pollens of grasses, trees, weeds, and Compositae, house-dust and storage mites, molds, animal danders, cockroach, latex and Tetranichus urticae extracts, with the exception of MP. Total IgE was 1751 lU/ml. Specific IgE to MP was 4.28 kU/1, but negative to grass pollens. The patient had a marked improvement to immunotherapy. In this patient, there was little crossreactivity between maize and grass pollens. (Gonzalo-Garijo 2004 ref.9083 7)

Reference:
Gonzalo-Garijo MA, Perez-Calderon R, Munoz-Rodriguez A, Tormo-Molina R, Silva-Palacios I. Hypersensitivity to maize pollen. Allergy 2004;59(3):365



[ 2 ]

Corn-induced hypersensitivity pneumonitis in a 50-year-old male farmer. He had experienced for 4 years recurrent episodes of fever, dyspnea and chest pain during the corn harvest season, 4-5 h after corn dust exposure. Precipitation bands were shown to a number of molds, corn extract and corn flour extracts. Pulmonary inhalation provocation test with corn extract resulted in bronchoconstriction within 5 minutes. (Martin-Garcia 2003 ref.13729 5)

Reference:
Martin-Garcia C, Hinojosa M, Porcel S, Leon F, Berges P. Corn-induced hypersensitivity pneumonitis. Allergy 2003 Jun;58(6):534-5.



[ 3 ]

In this study, symptoms suggestive of allergy were found in 90% of the farm workers, compared with only 4% of the control group. However, total IgE levels of the farm workers were not significantly raised and only 40% had positive radio-allergosorbent tests against specific allergens. The authors suggest that mechanisms other than allergy must be considered responsible for the farm workers' symptoms. (van Niekerk 1989 ref.3009 5)

Reference:
van Niekerk LS, Weich DJ Respiratory symptoms and specific IgE in workers on a maize farm. [Afrikaans] S Afr Med J 1989;76(10):562-5




Information supplied from an abridged section of:
Allergy Advisor - Zing Solutions
http://allergyadvisor.com/index.html

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Allergy Advisor  - Food Additive and Preservative Allergy and Intolerance Database


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