Bloodworm Allergies

Bloodworms are the larvae of insects called chironimidae, or midge flies. They develop in freshwater environments such as rivers and lakes and are often used as fish food. Bloodworms can cause allergic reactions in fish food workers, fish owners and people who are exposed to them in the wild by activities such as fishing or from living nearby.

Chironimidae

• Chironimidae, or midge flies, are non-biting insects that look similar to mosquitoes. According to the website Waterwereld, they swarm in watery areas and lay eggs in freshwater bodies, much like mosquitoes. Their larvae develop at the bottom of freshwater lakes and rivers, where they live along the sediment and debris. Their name comes from their red color; in order to adapt to low-oxygen environments, their blood contains red pigmentation that bonds with oxygen.

Ecology

• In the wild, bloodworms are eaten by many bottom-feeders, including freshwater fish, shrimp, salamanders, lobsters and insects. According to Waterwereld, they are high in protein and offer more calories per insect than many other small freshwater prey. They are numerous and basically defenseless, making them an excellent food source.

Exposure

• Humans come into contact with bloodworms in the wild or in fish food. According to the website ImmunoCAP, worldwide scientific studies link proximity to freshwater bodies and bloodworm exposure. They report cases in Japan, the UK, Germany, and the state of Wisconsin that trace allergic reactions to bloodworms from nearby lakes or rivers. Also, a study in the Journal of Investigational Allergology and Clinical Immunology entitled "Allergy to chronomid larvae (red midge larvae) in non professional handlers of fish food" finds that exposure to bloodworms in fish food sometimes causes allergic reactions.

Allergic Reactions

• ImmunoCAP reports various allergic reactions to bloodworms. When inhaled, they act as a respiratory allergen, and studies in both Korea and Japan conclude that they are a leading regional cause of asthma. Another study reported by ImmunoCAP found that a fish hobbyist developed eczema, a skin condition including dryness, flakiness and rashes, from bloodworm exposure. The article, "Allergy to chironomid larvae (red migde larvae) in non professional handlers of fish food," reports symptoms including rashes, rhinoconjunctivitis (itchy eyes and stuffy nose), dyspnea (shortness of breath), and dysphagia (difficulty swallowing).

Cross-Allergens

• ImmunoCAP reports that bloodworms react with various other allergens. Some common allergens that they cross-react with include dust mites, moths and mosquitoes. When allergens cross-react, new allergic reactions occur that otherwise might never have been an issue. For example, the website Clinical and Molecular Allergy relates that apples cross-react with birch trees in such a way that apple allergies usually only manifest themselves when combined with birch allergies.