Scallop is a food which may result in allergy symptoms in sensitised individuals.

Scallop Allergy Test: Allergen Exposure

Scallop is the name for any one of several species of saltwater clams or marine bivalve molluscs in the family Pectinidae. They are found throughout the world’s oceans, although the largest populations are centred on the Indo-Pacific region, and have been both collected and farmed by humans for hundreds of years.

Both the muscle (the scallop) and the roe (the coral) are edible. The former is white, with a firm texture and mild flavour, while the latter is softer in texture and a bright orange colour. In some markets whole scallops are sold with the coral already removed. They are also commonly available shelled, packed and frozen.

Scallops form part of a number of regional cuisines around the world. In Spain, they are often baked in their own shell with bread crumbs, ham, and onions. In France, the dish Coquilles St Jacques Parisienne consists of scallops cooked with mushrooms and whhite wine. They may be added to salads, pasta dishes or served as part of a seafood cocktail.

In Japan, they are a common ingredient in seafood soups, and may also be served raw as sushi or sashimi. In Cantonese cuisine, dried scallops are used, known as conpoy. Smoked scallops are sometimes served as appetizers or as an ingredient in the preparation of various dishes.

Scallops are low in saturated fat, and provide a good source of vitamin B12, calcium, iron, magnesium, potassium, zinc and copper, as well as a very good source of protein, phosphorus and selenium.

Scallop Allergy Test: Allergen Description

No specific allergens present in scallop have been characterised, although a number of allergenic proteins have been identified, particularly tropomyosin.

Scallop Allergy Test: Potential Cross-Reactivity

Allergy to scallop is most often associated with allergy to other related molluscs. Cross-reactions are found between molluscs, especially within the same class (bivalves, cephalopods or gastropods).

Therefore those allergic to bivalves (clams, mussels, oysters, and scallops) are likely to react to other bivalves, while those reacting to gastropods (abalone, limpets, snails, winkles and whelks) are likely to react to other gastropods.

Cross-reactivity between crustaceans and molluscs has been demonstrated.

Scallop Allergy Test: Clinical Experience

Severe adverse reactions to scallops have been described, requiring emergency treatment.

Shellfish, which includes scallop, is one of the more common food allergies, and usually persists throughout the patient’s lifetime. The majority of people (around 60%) of shellfish-allergic people experience their first allergic reaction as adults.

Symptoms can be severe and potentially life-threatening, including anaphylaxis. Even very small amounts of shellfish can provoke a reaction.

Exposure to the steam from cooking shellfish has been reported to cause an allergic reaction in some cases, due to the presence of allergenic proteins in the steam.

Other reactions

Seafood may contain high levels of histamine.

Shellfish poisoning is a potential consequence of ingesting shellfish contaminated with any one of a number of toxins. Symptoms may include nausea, vomiting, abdominal pain and diarrhea; chills, fever or headache; conjunctival irritation, sneezing and rhinorrhea and even paralysis.