SELECTED ARTICLES FROM THE RECENT LITERATURE 2004
11/15/04
Immunology of mosquito allergy
Summary
Background - Large local and occasional systemic reactions to mosquito (Mosq) bites are a common and often distressing clinical problem. Only in recent years has the immunologic basis of such reactions been clarified to some degree.
Findings - Mosq allergy was reviewed recently by Peng and Simons, leading investigators in this area of study. They pointed out that immune mechanisms underlie most Mosq reactions. Antibodies of IgE and IgG isotypes as well as T cell immunity may play pathogenic roles. The saliva of the Mosq is the major source of clinically relevant allergens. However, because most commercial allergen extracts used fordiagnosis in clinical settings are of whole body and not salivary origin, skin testing may not be sufficiently sensitive or specific. As a result, Mosq allergy may be under diagnosed.
Recombinant salivary allergens are currently being developed. An interesting facet of Mosq allergy is that an acquired desensitization may occur in older children after repeated bites. Such desensitization may not occur until adulthood in some individuals.
Reference
Int Arch Allergy Applied Immunol 2004;133:198-209
Editor's Comments
Over the years, I have been consulted about a number of children and adolescents with quite large (sometimes frightening to parents) local reactions to Mosq bites. Such excessive reactions appeared to be much less frequent in adults even though they had been bitten repeatedly over the years. With the lack of reliable Mosq allergenic extracts for testing/treatment, there was little we could do to investigate/treat such individuals other than advising adequate use of DEET-containing repellents and optimism that such excess reactivity would likely decrease in adulthood. Hopefully, the immunologic advances reviewed above may lead to effective immunotherapy where indicated.
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