There are several conditions related to seafood allergies. Having other types of allergies, particularly hay fever, asthma or eczema, predisposes a person towards food allergies.

Other related conditions include:

• Histamine fish poisoning. Some types of spoiled fish (e.g., anchovies, mackerel, mahi-mahi, tuna) contain histamines, the chemicals that trigger allergy symptoms in humans. When a person eats spoiled fish, these histamines can cause hives and flushing very similar to an allergic reaction. However, this reaction is actually a type of food poisoning and not a true allergic reaction. Histamine fish poisoning is very common.
  
  
• Anisakis allergy. A reaction to the parasitic worm Anisakis can mimic a seafood allergy. This intestinal parasite is found in fish and other types of seafood and is considered to be a food allergen capable of producing an allergic reaction. However, this parasite is not a true part of the fish and therefore cannot be considered a seafood allergen. A reaction to this worm usually occurs in raw or undercooked fish.
  
  
• House dust mite-crustacean-molluscs syndrome. There are strong similarities in the allergens found in some kinds of shellfish (e.g., shrimps, mussels, oysters) and those found in some commonly inhaled particles found in the home. The house dust mite-crustaceans-molluscs-syndrome is a type of cross-reaction. It usually involves a person becoming sensitized to a household allergen (often dust mites) and then having an allergic reaction to shellfish (sometimes even the first time they are consumed).
  
  
• Occupational seafood allergy. As the consumption and production of seafood rises, there are increasing reports of allergic reactions taking place in occupational settings. Those who work with the processing of crabs, prawns, mussels, fish and fishmeal are often exposed to skin and aerosolized contact with these foods. As a result, more workers are reporting instances of on-the-job allergic reactions.
  
  
• Red Sea coral contact dermatitis. Skin contact with fire coral can cause hives or blisters to develop on the skin (contact dermatitis). Individuals who have a seafood allergy are more likely to be susceptible to this condition.
  
  
• Aquarium allergy. Because dried pet fish food is often made up of the proteins of brine shrimp and other seafood species, it can cause an allergic response in some individuals. The dried food becomes easily aerosolized and can be inhaled, triggering allergic respiratory diseases such as asthma, allergic rhinitis and bronchitis.
  
  
• Benzoate allergy. This is a type of reaction to benzoate preservatives that are used to treat many kinds of shellfish after they are caught. Many people are allergic to this type of additive. Because shellfish are often treated with very high amounts of the additive, reactions in allergic individuals can be severe.