House dust mite-specific immunotherapy and tropomyosin sensitizations: harm or benefit for patients?

Background Allergenic tropomyosins are highly cross-reactive panallergens found in various invertebrates. Sensitized patients can develop allergic responses ranging from oral allergy syndrome to severe anaphylactic reactions after the ingestion of tropomyosin-containing food. The usual routs of sensitization to tropomyosin include the airborne exposure to various mites and cockroaches and the oral intake of crustaceans and mollusks. There were also reports of patients with combined mite and seafood allergy who had experienced a worsening of food allergy symptoms during house dust mite-specific immunotherapy (HDM-SCIT). Therefore, a possibility that mite tropomyosin present in allergen extracts can cross-sensitize patients receiving HDM-SCIT and thus induce food allergy is still investigated.Our aim was to assess the occurrence and the clinical relevance of tropomyosin sensitizations in HDM-SCIT-treated patients.