[Cow's Milk]      [Egg]      [Fish]      [Crustacea]

1. COW' MILK [more Informations]

          Throughout the world, cow's milk (Bostaurus) is used for the majority of human milk consumption. IgE-mediated sensitivity to cow's milk is one of the most common food allergens. The overall prevalence of cow's milk allergy in infants and children worldwide is estimated to be between approximately 2.5% in the first 3 years of life[9-11]. Symptoms often begin at age 3 months or younger, but many children lose sensitivity by age 3. Cow's milk allergy in adults is rather unusual. It is often manifested in children by vomiting and diarrhea, with approximately one-third to one-half of those affected experiencing skin manifestaons such as atopic dermatitis (AD), urticaria, and angioedema, or erythematous rashes.

         Cow's milk comprises a number of proteins. Traditionally, two major groups of cow's milk proteins have been identified: caseins, which comprise 80% of the totle protein, and whey proteins, which contribute 20% of the totle. Caseins are phosphoproteins that precipitate from raw skim milk after acidification to pH4.6 at 20°C, whereas whey proteins remain in the fluid("serum") after the precipitation of caseins[12]. The nomenclature of specific milk proteins utilizes a Greek letter with or without a subscript preceding the class name to identify the family of proteins. The genetic variant of the protein is indicated by an upper case Arabic letter with or without a numerical superscript following the calss name. Post-translational modifications are added in sequence. Many milk proteins are heterogeneous[12]. Characteristics of the major milk proteins are here!

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2. EGG [more Informations]

         Eggs from chickens (Gallus domesticus) are wildly used for human consumption. Egg allergy is one of the most frequently implicated causes of immediate food-allergic reactions in children in the U.S and Europe[25]. Frequently, egg sensitivity disappears by the fourth or fif th year of life or no later than the first decade of life; however, one third of individuals have clinical sensitivity that alsts ovr 6 years[25]. Although there is eextensive cross-reactivity among the proteins from various birds, hans eggs tend to be slightly more allergenic than duck eggs[26]. The egg white (albumin) is more allergenic than the yolk. Egg white proteins have been studied extensively, and most have been purified and acid sequences determined.

         Eggs are composed of 56 to 61% egg white and 27 to 32% egg yolk. The egg white is approximately 87 to 89% water and 9 to 11% protein, whereas the egg yolk contains 50% water, 32 to 35% lipid, and 16% protein[27]. The predominant protein in the egg white is ovslbumin, comprising 54% of the protein present. Other major proteins in the egg white are ovotransferrin (12%), ovomucoid (11%), ovomucin (3.5%), and lysozyme (3.4). In addition to these proteins, a variety of 180 and 400 kDa. Ovoinhibitor is a 44-kDa protein whose amino acid sequence is known and whose gene sequence has been obtained by cDNA cloning[28]. Ovoflavoprotein has been found in both egg white and egg yolk, and is known to be a riboflavin-binding protein. Avidin composes 0.5% of egg white protein. It is a heterogenous tetrameric glycoprotein with a molecular weight between 66 and 69 kDa, and acts as a biotin-binding protein. Other proteins inclode ovomacroglobulin, the G2, G3 globulins (which are not well characterized), and aystatin, an inhibitor of cysteine proteases. The characteristcs of egg white proteins are summarized here!

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3. Fish [more Informations]

         The consumption of fish and inhalation of cooling vapors are causes of IgE-mediated reactions. There have been no published reports on the prevalence of IgE-mediated reactions to a particular species of fish, as most studies refer only to cod or to "fish" in general. However, fish is one among the most commonly implicated allergenic foods, and has been incriminated in fatal anaphylactic reactions[55]. Although the true prevalence of fish allergy os unknown, incidence of fish hypersensitivity is observed to be higher in countries where fish consumption is above average. For example, codfish may be the most common food allergy in scandinavian countries[56].

         Most edible fishes belong to class Osteichthyes. Sharks are not in this class, as they are cartilaginous fish (orser Squaliformes). The most commonly consumed fishes in the U.S. belong to only a few orsers: Clupeiforms (salmons, trouts, whitefishes, smelts, pikes, herrings, sardines, anchovies, shad, menhadens, and alewives), Perciformes (bases, perches, dolphins, snappers, groupers, orange roughy, redfishes, rockfishes, mackerels, swordfishes, and tunas), Gadiformes (cosfishes, pollocks, haddocks, and hakes). Pleuronectiformes (flounders, halibuts. and soles) . and Cypriniformes ( carps and catfishes)[57].

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4. CRUSTACEA [more Infermations]

         At least 30 edible species of crustacea are commonly consumed in the U.S.  The crustacean family (phylum Arthropoda, class Crustacea) includes shrimp, prawns, crabs, lobsters, and crayfish, and is a common cause of food hypersensitivity[85]. Although the prevalence is not known, researchers have estimated that more than 250,000 people in the U.S. have potential for developing allergic reactions to shellfish[86]. Like fish. a higher incidence of allergy to shellfish would be expected in geographic ateas where more is consumed on a regular basis.