Maize food allergy: a double-blind placebo-controlled study.
BACKGROUND
Maize allergy is not very common especially in Europe. The number of studies that address IgE mediated maize allergy is all too few.


OBJECTIVE
Evaluate subjects with a history of maize allergy by double-blind, placebo-controlled food challenge; identify the spectrum of symptoms manifested during challenge; determine the lowest provocation dose (PD) during challenge; determine the performance characteristics of maize skin prick test and specific IgE.


METHODS
Twenty-seven patients with a history of maize allergy were enrolled to be evaluated by skin test, specific IgE and double-blind placebo-controlled maize challenge.


RESULTS
Forty-eight percent of the patients were challenge positive. PD range was 0.1-25 g. Fifty-four percent of the maize allergic subjects had a PD that was < or = 2.5 g; two subjects reacted to 100 mg of maize. Comparison of maize specific IgE levels and skin test results to the challenge results revealed the following (specific IgE level/skin testing): sensitivity 1.00/0.846, specificity 0.077/0.384, positive predictive value 0.520/0.579, and negative predictive value 1.00/0.714.


CONCLUSIONS
Maize is a cause of IgE-mediated allergic reactions to foods in adults and children. Nearly half of the subjects recruited were confirmed by challenge to be allergic to maize. Twenty-three percent of the positive challenge patients manifested symptoms that involved two organ systems, thus fulfilling the criteria for maize induced anaphylaxis. Maize is allergenic and can pose a risk for symptomatic food allergy at a dose of 100 mg.
Scibilia
J
J
Unit of Allergology and Clinical Immunology, A.O. Niguarda Hospital, Milan, Italy.
Pastorello
E A
EA
Zisa
G
G
Ottolenghi
A
A
Ballmer-Weber
B
B
Pravettoni
V
V
Scovena
E
E
Robino
A
A
Ortolani
C
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D000707:Anaphylaxis / Q000097:blood / Q000175:diagnosis / Q000209:etiology / Q000276:immunology; D052179:Antigens, Plant / Q000009:adverse effects* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003718:Denmark; D004306:Dose-Response Relationship, Immunologic; D004311:Double-Blind Method; D005260:Female; D005512:Food Hypersensitivity / Q000097:blood / Q000209:etiology / Q000276:immunology*; D006801:Humans; D007114:Immunization; D007073:Immunoglobulin E / Q000097:blood* / Q000276:immunology; D007558:Italy; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D012882:Skin Tests; D013557:Switzerland; D055815:Young Adult; D003313:Zea mays / Q000009:adverse effects* / Q000276:immunology
D052179:Antigens, Plant; D007073:Immunoglobulin E