Allergy Oyster Fluorescence Assay Blood

Oyster is a bivalve mollusk. The edible oysters belong to two genera, Ostrea and Crassostrea. Oysters in warm seas may take 18 months to reach market size, while in cooler seas, up to 5 years. Oyster has been reported as both an ingested and occupational allergen. Oysters are eaten fresh and canned, but also smoked. The Japanese have extensive off-bottom culture, especially in protected bays. The Chinese have all over the world exported a pungent sauce made from oyster extract and used for flavoring. Allergies to molluscs are diagnosed using the same procedures as for other food allergies. A detailed patient history is first taken. Skin and laboratory tests are then used to identify the foods likely to cause allergic reactions, which can then be eliminated from the diet. Commercially available extracts from molluscs include abalone (Haliotis spp.), blue mussel (Mytilus edulis), clam (Ruditapes spp.), octopus (Octopus vulgaris), oyster (Ostrea edulis), pacific squid (Todarodes pacificus), scallop (Pecten spp.), snail (Helix aspersa) and squid (Loligo spp.). There are some pitfalls in investigating allergy to molluscs as the identification of the species eaten may not be simple, especially if a restaurant has substituted a cheaper mollusc such as limpet for an expensive one such as abalone. Skin prick testing appears to identify almost all cases of food allergy with some false positives. Skin prick test using fresh food often improves the identification of the suspected food. Traditional allergy tests utilize the Skin Prick method (also known as a Puncture or Scratch test) to determine whether an allergic reaction will occur by inserting possible triggers into your skin using a needle prick. If you are allergic to the substance, you are forced to suffer through your body's reaction to the allergen. In vitro tests on sera are also helpful but there is insufficient data to assign probabilities of reaction to levels of specific IgE. Oral challenges have rarely been made with molluscs and the lowest threshold dosages remain to be elucidated. They range from mild oral allergy syndrome (itching of the lips, mouth, or pharynx, and swelling of the lips, tongue, throat, and palate), through urticaria (hives), which is probably the most commonly reported symptom, to life-threatening systemic anaphylaxis (difficulty breathing, drop in blood pressure, and even death). Symptoms may involve the skin (itching, swelling), the gastro-intestinal tract (nausea and diarrhoea) and also respiratory symptoms (asthma, rhinitis). Most reported symptoms occurred within 90 minutes of ingesting the food.