10/15/03 Allergic reactions to Triatoma bitesSummaryTriatoma (kissing bug) bites are best known as vectors in the disease trypano somiasis (Chaga's disease) in certain parts of the world. However, Triatoma bites are causes of localized cutaneous allergic reactions at the bite site and occasional systemic (anaphylactic reactions) in western and southwestern USA. This subject was reviewed by Moffitt et al of the University of Mississippi's Medical Center. They reviewed relevant articles about Triatoma bites in the USA, with most allergic reactions reported in the West/Southwest. Reactions occur typically at night with a bite on uncovered skin of a sleeping person. Allergic reactivity has been demonstrated against salivary components in 2 different Triatoma species (not cross-reactive). Limited trials of immunotherapy with a crude salivary gland extract appeared to be beneficial in uncontrolled trials in a small number of patients. However, the lack of a standardized commercially prepared antigen has limited diagnostic, epidemiologic and therapeutic approaches. Reference Ann Allergy Asthma Immunol 2003; 91:122-28 Editor's Comments My recollections from my time stationed in the San Joaquin valley of California was that Triatoma bites were a significant cause of painful/pruritic local skin reactions. .I did not personally observe any anaphylactic reactions to Triatoma bites in the limited number of cases I saw. Also, for most individuals, they have not been bitten repeatedly by Triatoma bugs so may not have become sufficiently sensitized. The various cutaneous reactions to such bites can be mistaken for herpes zoster, erythema multiforme and the ubiquitous catch-all diagnoses of "spider-bite. A Triatoma salivary allergen has been characterized and actually produced by recombinant DNA technology in the CDC (J Immunol. 2001 ;167:2694-9) Further investigation of this under appreciated and inadequately studied problem appears warranted.
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