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

Grouper Allergy Test: Allergen Exposure

Groupers are any of a number of species of teleost fish in the subfamily Epinephelinae. They are closely related to the sea basses. Groupers range in size, with some individuals weighing as much as 100kg. Many species are important to humans as food fish, and are farmed as well as being caught in the wild.

Unusually, rather than being sold chilled or frozen, groupers are often offered for sale live. The flesh is white and flaked when cooked, and contains no intramuscular bones. The skin is usually removed before cooking as it is tough and has a strong flavour.

Grouper is a particularly lean fish, so is increasingly selected by health conscious consumers. It is a good source of protein, as well as calcium and iron.

Grouper is prepared in a number of ways, including poaching, steaming, baking, broiling, sautéing and grilling. Due to its low fat content it is often basted during dry heat cooking to maintain moistness.

It is also used as an ingredient in various stews, salads and pasta dishes, as well as sauces.

Grouper Allergy Test: Allergen Description

No specific allergens present in grouper have been characterised, although a number of proteins have been identified.

Grouper Allergy Test: Potential Cross-Reactivity

Species within groups of fish, like Gadiformes (examples: codfish and hake) and Scombroid fishes (examples: mackerel and tuna) seem to share allergenic components. The overlap of allergen specificity between the groups seems to be moderate or even small.

Cross-reactivity to grouper within the order Perciformes can therefore be expected, which includes perch, darters and sea bass.

Grouper Allergy Test: Clinical Experience

Sensitisation to fish allergen is common. Fish, including grouper, is a potential cause of food allergy and atopic dermatitis.

Immediate allergic reactions may follow ingestion of even minute amounts of fish.

Symptoms can include oral allergy syndrome, generalised urticaria, facial angioedema and anaphylaxis.

Because patients react to both cooked and raw fish, it is assumed the allergens are heat-resistant. However, more recent studies indicate that patients may react differently to processed food and that allergic reactions may be species-specific.

It has been reported that some fish allergic persons can exhibit allergic symptoms due to the steam (airborne allergens) from cooking fish.

Other reactions

Anisakiasis, or herring worm disease, is a parasitic disease caused by nematodes (worms) that attach to the wall of the esophagus, stomach, or intestine of the grouper.

Symptoms can include abdominal pain, nausea, vomiting, abdominal distention, diarrhea, blood and mucus in stool, and mild fever. Allergic reactions with rash and itching, and infrequently, anaphylaxis, can also occur.

Grouper and other large reef fish may be contaminated by ciguatera toxin, particularly in the Caribbean Sea, Hawaii, and coastal Central America. The toxin can cause nausea, pain, cardiac, and neurological symptoms in humans when contaminated fish is ingested.

Fish allergy is sometimes confused with a reaction to histamine in spoiled fish.