Shellfish food allergy

The most frequent elicitators of food allergy in children are peanuts and tree nuts [ 17]. In France the prevalence of food allergy has been estimated to be 3.2% [18]. Furthermore, in this study, food was identified as the most common cause of anaphylaxis. Here the major identified food allergens besides peanuts and tree nuts were shellfish, wheat and lupine flour [18]. 

Ranee et al. (2005) conducted a questionnaire-based survey of food allergy in 2716 school children in France. Four cases of molluscan shellfish allergy were reported to mussels, snails, and oysters among this group. Thus, the self-reported prevalence of molluscan shellfish allergy in this population of children was 0.15%. 

FIGURE 4.1 Percent identity matrix for tropomyosins from molluscan shellfish, crustacean shellfish, insects and mites, and vertebrate sources. Compiled with the assistance of John C. Wise, Bioinformatics Specialist, University of Nebraska, Food Allergy Research Resource Program. 

Prevalence of Sensitization to Shellfish in Various Countries among Individuals (Adults and Children) with Food Allergy... 

Food allergy, particularly to peanuts, is the most common cause of anaphylaxis outside hospital (Bock et ah, 2001), yet there are other common food causes such as shellfish, fish, milk, soy, wheat, and eggs (Asero et ah, 2007). These foods may not only cause fatal or near-fatal reactions, and they also tend to induce "persistent sensitivity" in most patients, in contrast to other foods such as milk, eggs, and soybeans, which are frequently associated with milder reactions and are usually "outgrown."... 

Ask the patient if he or she has any allergies to food or medication. The patient may be aware of food allergies such as shellfish, but unaware of allergies to medication. However, patients who are alleigic to shellfish are also allergic to some medications. 

The importance of molluscan shellfish allergy is increasingly recognized. The European Union recently added molluscan shellfish to the list of most commonly allergenic foods in Europe (EESA, 2006). Although not knovm... 

The prevalence of allergies fo specific foods is unknown for the most part. Good estimates exist of the prevalence of milk allergy in infancy (Hosf and Halken, 1990) and peanut and tree nut allergy throughout the life span (Sicherer et ah, 1999). However, the prevalence of allergies to seafoods including molluscan shellfish is not precisely known. 

These two surveys are in reasonably good agreement regarding prevalence estimates for molluscan shellfish allergy. That is especially true since all the ages were included in the surveyed population of Sicherer et al. (2004) while only children were involved in the French survey (Ranee et ah, 2005). Hypothetically, sensitization to molluscan shellfish might develop later in life than for other foods because of the infrequent consumption pattern. 

The number of sfudies estimating the comparative prevalence of molluscan shellfish allergy is limited. The frequency of consumption of molluscan shellfish mighf be higher in some of the locales where such studies have been performed. Clearly, more comparative clinical data would be helpful. However, the molluscan shellfish certainly seem to be a comparatively common allergenic food in some locales and among some populations. 

While all humans have IgE antibodies fhaf are involved in defense against parasitic infections, only humans who are predisposed to the development of allergies will produce IgE antibodies upon exposure fo certain protein allergens present in their environment including their diet. Only a few of the many proteins found in foods are capable of sfimulating the production of specific IgE antibodies in susceptible individuals (Taylor, 2002). With molluscan shellfish, only one, or perhaps a few, of the numerous proteins is known to provoke the production of IgE antibodies that specifically recognize one or more species of molluscan shellfish. 

H. Food-dependent, exercise-induced molluscan shellfish allergy... 

The only proven therapy for molluscan shellfish allergy is strict dietary avoidance. Problems may arise with avoidance diets when clam is present due to mislabeling or to cross-contact during food processing (Taylor and Hefle, 2005 Taylor et ah, 1986,1999). The food industry typically develops allergen control programs to prevent the occurrence of undeclared allergenic residues in other foods (Taylor et ah, 2006). The industry often uses... 

Causes are largely unclear complaints of food intolerances are often made, but clear evidence of specific and consistent adverse effects is hard to obtain (a distinction is drawn here from genuine dietary allergy which responds to avoidance of the offending item, for instance shellfish, and use of oral sodium cromoglicate). The basis of irritable bowel syndrome rests somewhere in the hinterland of perception of dysfunction, and otherwise normal but exaggerated physiological colonic responses. 

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