food allergy ( fa ) is a common disease that is rapidly increasing in prevalence for reasons that remain unknown . recent estimates suggest that around 17 million people in europe suffer from allergies triggered by foods such as milk , eggs , peanuts , tree nuts , or seafood , and an increasing number are seeking treatment through primary care and hospital emergency departments . a recent national survey of allergies in the united states showed an increase in the prevalence of food allergies from 3.4% in 19971999 to 5.1% in 20092011 . fa can have a significant effect on an individual 's quality of life and physical functioning and can also be costly in terms of medical visits and treatments . food allergies manifest various symptoms in the skin , gastrointestinal tract , and airways as a result of adverse responses to a food protein via ige - mediated or non - ige - mediated immune mechanisms . allergic responses to food present as inflammation due to cellular responses activated against the food allergen . there is a lack of information on the role of nutrition versus only food avoidance in the management and natural history of food allergy . little information is also known about the effect of a nutrition consultation in this process . furthermore , the role of the dietician and the diagnostic and therapeutic value of the elimination diet has not been established and extensively investigated . the aim of the present study is analyze the clinical characteristics and nutritional status of patients with food allergies followed in a tertiary centre of allergy and immunology . this was a retrospective study that assessed the data records of patients who were evaluated in the food allergy out - patient clinic of the clinical hospital of federal university of uberlandia , between february 2009 and february 2012 . data from age , sex , gestational age , delivery birth type , breastfeeding period , age of introduction of complementary formulas based on cow milk protein , anthropometric parameters , and foods implicated in allergies were obtained from the patient records . the diagnosis routine of food allergy was performed based on the history and laboratory tests ( specific ige , skin prick test ) . since there are no effective laboratory methods for the diagnosis of non - ige - mediated fa , suspected in patients with symptoms suggestive of proctocolitis and enterocolitis , or in patients with diagnosis of eosinophilic esophagitis and atopic dermatitis moderate to severe , an elimination diet without a suspected allergenic protein and subsequent oral food challenge , which was open for children younger than 3 years and double - blind for children above 3 years , was used for diagnosis [ 5 , 6 ] . the anthropometric data of patients seen for the first time was evaluated according to z - scores for weight - for - age , height - for - age , and body mass index ( bmi ) . who - antro software version 3.2.2 , january 2011 , available from ( http://www.who.int/childgrowth/software/en/ ) was used to calculate z - scores and the world health organization growth charts were used as reference values . the kolmogorov - smirnov test was used to determine whether variables were normally distributed . for continuous variables , all analyses were conducted using graph pad prism 5.0 ( la jolla , california , usa ) . the study was approved by the human research ethics committee of federal university of uberlandia . in the period studied , the medical files showed that 389 different patients were evaluated in the out - patient clinic of food allergy . of these , 35 patients did not undergo any consultation or medical records did not present data regarding the query . among the 354 patients that were evaluated by physicians in our unit , 228 ( 69.1% ) had a confirmed diagnosis of food allergy , while the diagnosis of food allergy was excluded in the remaining 126 ( 30.9% ) . the median age of patients with an fa diagnosis was 10 months ( 1193 months ) while the group without fa was 36.5 months ( 1216 months ) . there was a significant difference between the ages of the groups ( p < 0.0001 by mann - whitney test ) . there were no statistical differences in sex , gestational age , birth type , breastfeeding period , and age of introduction of complementary formulas based on cow milk protein , as shown in table 1 . the most frequent symptoms in patients with food allergy were nausea and vomiting in 118 ( 51.7% ) , abdominal pain in 104 ( 45.6% ) , diarrhea in 73 ( 32.0% ) , fresh rectal bleeding in 71 ( 31.1% ) , failure to thrive in 55 ( 24.1% ) , urticaria in 50 ( 21.9% ) , constipation in 19 ( 8.3% ) , dysphagia in 8 ( 3.5% ) , and food aversion in 8 ( 3.5% ) . the diagnosis of non - ige - mediated allergy was performed in 168 ( 73.68% ) , while the diagnosis of ige - mediated food allergy was performed in 75 ( 32.89% ) . the diagnosis of mixed ige and non - ige - mediated food allergy was done in 15 ( 6.57% ) . the z - scores for weight - for - age , height - for - age , and body mass indices- ( bmi- ) for - age showed less significant values in the fa group compared with the non - fa group by mann - whitney test , with values of p = 0.0005 , p = 0.0030 , and p = 0.0066 , respectively ( table 1 ) . indeed , 18.4% presented with a low weight - for - age z - score ( < 2.0 standard deviation ( sd ) ) , 15.9% with a low height - for - age z - score ( < 2.0 sd ) , and 15.4% with a low bmi - for - age z - score ( < 2.0 sd ) . a significant difference in low levels ( < 2.0 sd ) by fisher exact test was found between the fa and non - fa groups only in height - for - age z - score ( p = 0.0189 ) , although the weight - for - age z - score analysis showed a p value that was close to significance ( p = 0.0549 ) . when we separated the groups with z - score less than 2 and up , there is no difference relative to the numbers of implicated food allergens . in bmi - for - age z - score less than 2 , 16 ( 51.61% ) of patients had one food allergy , 9 ( 29.03% ) had two foods involved , and 6 ( 19.36% ) had three or more foods , while in group with z - scores up 2 , 117 ( 59.40% ) had one food implicated , 36 ( 18.28% ) had two foods , and 44 ( 22.32% ) had three or more foods . figure 1 represents the comparison between z - scores of food allergy patients and a reference curve of growth in childhood . food allergy patient curve is lower and presents a left variation in evaluation with reference to the three parameters ( weight - for - age , height - for - age , and bmi - for - age ) demonstrating the impairment in growth parameters . the incidence and prevalence of food allergies are believed to be increasing in several countries . dietary antigens induce a local hypersensitivity reaction impairing the intestine 's barrier function , leading to the continuation of inflammation . the consequences of inflammatory responses may be severe and manifest as impaired growth , increased symptoms , and poor quality of life . we did not find an association between sex , gestational age , delivery birth type , breastfeeding period , and age of introduction of complementary formulas based on cow milk protein with the development of fa . however , the number of medical records without any analyzed data was a limiting factor in data analysis . approximately one - third of the patients did not have the studied data clearly outlined in their medical report , indicating that it is important to improve the completion of data in documents . in the present study , cow 's milk protein was responsible for fa in more than 90% of patients with non - ige - mediated disease and more than 78% in patients with an ige - mediated mechanism . similarly to other studies , besides cow 's milk , the foods most commonly implicated with allergy in infants were hen 's eggs , soy , and wheat . in contrast to that found in other studies , allergy to corn protein was found in 13.59% of patients , demonstrating a peculiarity of this region where there is intense corn consumption due to cultural factors . one study performed in brazil and focused on infants with cow milk allergies showed that , among the 159 patients seen at first evaluation , 15.1% presented with a low weight - for - age z - score ( < 2.0 sd ) , 8.7% with a low weight - for - height z - score ( < 2.0 sd ) , and 23.9% with a low height - for - age z - score ( < 2.0 sd ) . we also found similar data in the present study , as shown in the results section . another study conducted on 99 patients with food allergies showed that patients with a milk allergy or multiple food allergies are at greater risk of developing growth problems or inadequate nutrient intake . in the present study , the control group was filled by patients that looked for the out - patient clinic with fa suspicion ; then it is possible that patients could have another clinical disorder that affected their growth data and express less significant differences between fa and control group . because of that , the comparative evaluation with who growth reference curves is important . the curves showed a clear impact in growth data found in fa group in all scores in comparison with reference values . more than 25% of children in both groups consumed less than 67% of the dietary reference intakes for calcium , vitamin d , and vitamin e . according to previous data , the present study showed lower z - scores in fa patients related to non - fa patients , suggesting difficulties in receiving adequate nutrient intake when a necessity to avoid specific proteins exists . this difficulty in establishing a diet and the presence of levels of z - score less than 2 apparently were related with absence of medical and nutritional information , once there are no significant correlation with number of the implicated foods in allergy . we also believe that the presence of non - ige - mediated fa promotes intestinal inflammation that can lead to difficulties in the absorption of other nutrients , which justifies the meeting of nutritional changes or even the admission of patients to hospital . these difficulties in a phase of life where there is a large increase in height and weight probably contributed to the difference in z - scores observed in patients with food allergies . one limitation of this study in respect to nutritional status is the use only of height , weight , and bmi , but these are only data possible in medical charts . the cohort studies will effectively show more accurate data , but that does not cut the value of the present study . in conclusion , fa patients had a lower growth rate in comparison with patients without fa . the early recognition of food allergies with the establishment of a diet excluding the implicated protein , in association with an adequate nutrient replenishment , is important to reduce the nutritional impact of food allergies .
background and aims . 
 food allergy ( fa ) is a common disease that is rapidly increasing in prevalence for reasons that remain unknown . objective . 
 the aim of this study was to analyze the clinical characteristics and anthropometric data of patients with food allergies followed in a tertiary centre of allergy and immunology . methods . 
 a retrospective study was performed that assessed the data records of patients with food allergy diagnosis , covering a period from february 2009 to february 2012 . 
 results . 
 354 patients were evaluated in the period ; 228 ( 69.1% ) patients had a confirmed fa diagnosis . 
 the z - scores for weight - for - age , height - for - age , and body mass indices - for - age showed lower significant values in the fa group compared with the non - fa group by mann - whitney test , with significance values of p = 0.0005 , p = 0.0030 , and p = 0.0066 , respectively . 
 there were no statistical differences in sex , gestational age , birth type , breastfeeding period , and age of introduction of complementary formulas based on cow milk protein between groups . conclusion . 
 fa patients had a lower growth rate in comparison with patients without fa . 
 the early recognition of food allergies with the establishment of protein - implicated diet exclusion , in association with an adequate nutrient replenishment , is important to reduce the nutritional impact of food allergies .