but sometimes to other proteins, such as fish collagen. The allergic reaction to shellfish and crustaceans such as lobster and shrimp is to a different protein, tropomyosin, so there is no cross-reactivity between fish and shellfish allergy. Cross-contact Cross-contact, also referred to as cross-contamination, occurs when foods are being processed in factories or at food markets, or are being prepared for cooking in restaurants and home kitchens. The allergenic proteins are transferred from one food to another. Fish parasite The food-borne parasite Anisakis is a genus of nematodes known to be present in intermediate host salt-water fish, anadromous fish that travel from oceans to rivers to breed, and squid. Anisakis are directly infective to humans when infected fish or squid is consumed raw or slightly processed, causing a condition called anisakiasis. Symptoms include severe abdominal pain, nausea, and vomiting. In addition, there can be an allergic reaction to Anisakis proteins, even if the food in question was frozen, killing the nematodes, or cooked before being consumed, as some of the nematode proteins are resistant to heat. Allergic reactions can include hives, asthma and true anaphylactic reactions. Occupational exposure An industry review conducted in 1990 estimated that 28.5 million people worldwide were engaged in some aspect of the seafood industry: fishing, aquaculture, processing and industrial cooking. Men predominate in fishing, women in processing facilities. Exposure to fish allergenic proteins includes inhalation of wet aerosols from fresh fish handling, inhalation of dry aerosols from fishmeal processing, and dermal contact through skin breaks and cuts. Prevalence of seafood-induced adult asthma is on the order of 10% (higher for crustaceans and lower for fish). Prevalence of skin allergy reactions, often characterized by itchy rash (hives), range from 3% to 11%. The fish-induced health outcomes are mainly due to the protein parvalbumin causing an IgE mediated immune system response. Exercise as contributing factor Exercise can be a contributing factor to an allergic food response. There is a condition called food-dependent, exercise-induced anaphylaxis. For people with this condition, exercise alone is not sufficient, nor consumption of a food to which they are mildly allergic sufficient, but when the food in question is consumed within a few hours before high intensity exercise, the result can be anaphylaxis. Fish are specifically mentioned as a causative food. One theory is that exercise is stimulating the release of mediators such as histamine from IgE-activated mast cells. Two of the reviews