wheat is a major staple of the diet worldwide and wheat allergy is defined as an adverse immunologic reaction to wheat protein .
depending on the route of exposure and the underlying immunologic mechanisms , wheat allergy are diagnosed as different forms of allergic diseases such as classic food allergy , food - dependent exercise - induced anaphylaxis ( fdeia ) , occupational asthma , rhinitis or contact urticaria .
ige mediated allergy to wheat may be presented with various severity from simple urticaria to anaphylaxis . in korea , only a few studies on wheat - induced anaphylaxis ( wia ) have been performed .
we herein report six cases of severe wheat allergy including wia and wheat - dependent exercise - induced anaphylaxis ( wdeia ) .
all the patients visited our allergy clinic for the evaluation of symptoms such as urticaria , dyspnea , or syncope .
history taking revealed that they ate wheat - containing foods before their symptoms had started .
their ages ranged from 29 to 65 years and mean  standard deviation ( sd ) of age was 45  14 years .
the mean  sd of the patient 's age at the onset of the symptoms was 38  10 years ( from 27 to 55 years ) .
one patient with wia and two patients with wdeia were males and the others were females .
all patients with wia had combined allergic diseases and only one patient with wdeia had allergic rhinitis .
there was no patient who took aspirin or nsaids which might enhance food induced anaphylaxis .
all six patients had skin manifestation , such as urticaria ( 100% ) and 4 of 6 had angioedema .
five patients had respiratory symptoms such as wheezing or dyspnea , and only one patient with wia had gastrointestinal symptoms .
all patients showed hypotension during the events of anaphylaxis and 4 patients had experienced loss of consciousness .
the mean  sd of the level of total ige was 512.20  668.86 iu / ml .
3 ) and another patient showed normal level of total serum ige ( no . 5 , 94 iu / ml ) .
wheat - specific ige detected by immunocap ( unicap phad , pharmacia & upjohn , uppsala , sweden ) showed class 1 in two patients and class 2 in the other two patients .
gluten - specific ige was increased as class 2 in 3 patients ( 2 wia and 1 wdeia ) and as class 3 in 2 patients ( 1 wia and 1 wdeia ) .
-5 gliadin - specific ige was increased in 4 patients , class 3 in 3 patients ( 1 wia and 2 wdeia ) and class 4 in one patient with wia .
the levels of gluten or -5 gliadinspecific ige were higher than wheat - specific ige in all six patients .
the patients showed a positive response in skin prick test with wheat as shown in table 4 .
all of them had positive results for skin prick tests for other foods : one patient ( no .
in addition , those with wdeia had positive skin prick test for common inhalant allergens . while 5 patients were diagnosed on the basis of repeated histories and specific ige to wheat proteins , one patient ( no .
5 ) suspected as having wdeia underwent an exercise provocation test 30 minutes after eating wheat - containing food . within 5 minutes after 6 minutes
free running , the patient developed generalized itching and urticaria . at 15 minutes , the patient complained of dyspnea and presented with hypotension ( systolic blood pressure 63 mmhg ) .
symptoms were resolved gradually after treatment , with restoration of normal vital signs and physical examination findings .
the three patients with wia were advised the life - long avoidance of wheat containing products and the others with wdeia were taught to avoid wheat - containing food , and importantly to avoid exercise for at least six hours when they accidentally ate wheat - containing food .
food allergy is increasing and the prevalence of food allergy is estimated to be 6 - 8% of children and 1 - 3% of adults .
wheat is an important part of human diet and one of the six most common foods causing allergy .
depending on the route of allergen exposure and the underlying immunologic mechanisms , wheat allergy may appear as classic food allergy affecting the skin , gut , or respiratory tract ; exercise - induced anaphylaxis ; occupational asthma and rhinitis ; or contact urticaria .
in addition , ingestion of wheat gluten may cause celiac disease ( t - cell - mediated intestinal inflammation ) , or dermatitis herpetiformis ( blistering skin eruption ) . with the exception of the latter two , specific ige to wheat proteins play a central role in all of the above . despite the high prevalence of wheat allergy in children , relatively little
the natural course of only a few patients with wheat allergy has been reported in the literature , and in these studies 25% to 35% of patients became tolerant in a 1- to 2-year period . in the study by keet et al .
, 35% of the children who had wheat allergy remained allergic during their teenage years . in some cases , it may lead to exacerbation of atopic dermatitis and gastrointestinal symptoms
. a unique form of allergy , wdeia , develops predominantly in young adults and adolescents .
a few cases of wia , which were enhanced by aspirin or nonsteroidal anti - inflammatory drugs , have been reported in adult patients .
recently , it has also been reported that fdeia could be dependent on the temperature . in this study , all of the cases of wia were adult - onset and 4 ( 67% ) of the patients had co - morbid allergic diseases .
most of them experienced urticaria , respiratory symptoms and hypotension during the events , but only one patient had gastrointestinal symptom .
four of the 6 patients showed increased levels of total ige than normal range and 3 patients with wdeia had positive responses to skin prick test with common food allergen and aeroallergens .
because of the difficulty of strict wheat avoidance , complete diagnosis for the patients who were suspected wheat allergy is critical . to diagnose wia or wdeia , food challenge test with wheat or exercise challenge test following wheat ingestion should be performed .
however , the provocation test is time - consuming and has a risk of inducing anaphylaxis . on top of that , the amount of food and the degree of exercise vary .
considering the risk of food challenge tests in patients with a history of anaphylaxis , in vitro tests using immunocap could be a useful method in clinical practice with definite history of anaphyalxis .
wheat proteins are classified depending on the basis of their solubility in a series of solvents : water ( albumins ) , dilute salt solutions ( globulins ) , aqueous alcohol ( gliadins ) , and dilute alkali or acid ( glutenins ) .
classic food allergy and atopic dermatitis are related to a wide range of water / salt - soluble and insoluble wheat proteins .
wdeia is usually known to be associated with gluten , particularly -5 gliadin and high - molucular - weight ( hmw ) glutenin subunits .
although most recent studies suggested major roles of hmw glutenin subunits and -5 gliadin in wia and wdeia , low molecular weight ( lmw ) glutenin subunits are also known to be involved in immediate type childhood and adult wheat allergies , including wdeia . in the study by park et al .
, 17 subjects with wia or wdeia showed strong positive specific ige response to -5 gliadin allergens , but not to wheat , indicating that -5 gliadin is the causative allergen in adults with wia . using the log - transformed specific ige ratio of -5 gliadin to wheat
, they found 100% sensitivity and specificity distinguishing patients with severe wheat allergy , such as wdeia or wia , from patients with other forms of wheat allergies in the 27 subjects .
all of the patients in our cases also showed stronger specific ige response to -5 gliadin than the response to wheat .
in korea , only a few studies reported the cases of wheat - induced anaphylaxis in adults .
we report six cases of wheat - induced anaphylaxis diagnosed on the basis of clinical history and specific ige of wheat proteins or provocation test . for immunologic evaluation of severe wheat allergy including wia and wdeia , it is important to measure specific ige to each component of wheat including gluten and -5 gliadin rather than measuring wheat - specific ige .
 wheat is a common cause of food allergy . 
 wheat - induced anaphylaxis ( wia ) and wheat - dependent exercise induced anaphylaxis ( wdeia ) are severe forms of immunoglobulin e ( ige ) mediated allergic reaction to wheat protein . 
 as the diagnosis of wia or wdeia is not easy because of the risk of oral challenge , identification of specific ige of various wheat proteins is helpful for diagnosis . in korea , there are only a few reports on wia in adults . 
 we report six cases of wia diagnosed on the basis of clinical history and specific ige of wheat proteins or provocation test . for immunologic evaluation of severe wheat allergy including wia and wdeia , 
 it is important to measure specific ige to each component of wheat including gluten and -5 gliadin not just measuring wheat - specific ige . 
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