Official reprint from UpToDate®
www.uptodate.com ©2017 UpToDate®

Large local reactions to mosquito bites

John M Kelso, MD
Section Editor
David B Golden, MD
Deputy Editor
Anna M Feldweg, MD


Reactions to mosquito bites are caused by an immunologic response to proteins in mosquito saliva. Many people who are bitten by mosquitoes develop an immune response to these proteins; however, only a small proportion of them develop clinically relevant allergic reactions (most commonly large local reactions).

This topic briefly reviews the types of reactions that may result from mosquito bites [1]. It also focuses on large local reactions to mosquito bites and their clinical features, pathogenesis, natural history, diagnosis, differential diagnosis, treatment, and prevention. Other issues related to insect bites are reviewed separately. (See "Insect bites" and "Prevention of arthropod and insect bites: Repellents and other measures".)


Typical (normal) reactions — Local cutaneous reactions to mosquito bites typically consist of immediate wheals (swelling) with surrounding flares (redness) that peak at 20 minutes and delayed, itchy indurated (firm) papules that peak at 24 to 36 hours and resolve over the next 7 to 10 days.

The typical clinical course of sensitization and natural desensitization to mosquito salivary was described initially in the 1940s. It evolves over months or years in an individual (table 1) [2]. People who have never been exposed to a particular species of mosquito do not develop reactions to the initial bites from such mosquitoes. Subsequent bites result in the appearance of delayed local skin reactions. After repeated bites, immediate wheals develop. With further exposure, the delayed local reactions wane and eventually disappear, although the immediate reactions persist. People who are repeatedly exposed to bites from the same species of mosquito eventually also lose their immediate reactions. The duration of each of these five different stages differs, depending on the intensity and timing of mosquito exposure. These typical reactions are annoying, but not dangerous. The immunologic basis of sensitization and natural desensitization to mosquito bites was described in the 1990s [3,4]. Both immunoglobulin E (IgE) and immunoglobulin G (IgG), as well as lymphocytes, appear to be involved in the development of local reactions. Serum mosquito salivary gland-specific IgE and IgG levels correlated significantly with the size of the immediate skin reaction to mosquito bites, while lymphocyte proliferation to mosquito antigens correlated with the delayed reaction.

Large local reactions to mosquito bites — Large local reactions are by far the most common type of allergic reactions to mosquito bites:


Subscribers log in here

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information or to purchase a personal subscription, click below on the option that best describes you:
Literature review current through: Mar 2017. | This topic last updated: Nov 18, 2015.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2017 UpToDate, Inc.
  1. Peng Z, Simons FE. Advances in mosquito allergy. Curr Opin Allergy Clin Immunol 2007; 7:350.
  2. MELLANBY K. Man's reaction to mosquito bites. Nature 1946; 158:554.
  3. Reunala T, Brummer-Korvenkontio H, Räsänen L, et al. Passive transfer of cutaneous mosquito-bite hypersensitivity by IgE anti-saliva antibodies. J Allergy Clin Immunol 1994; 94:902.
  4. Peng Z, Yang M, Simons FE. Immunologic mechanisms in mosquito allergy: correlation of skin reactions with specific IgE and IgG antibodies and lymphocyte proliferation response to mosquito antigens. Ann Allergy Asthma Immunol 1996; 77:238.
  5. Simons FE, Peng Z. Skeeter syndrome. J Allergy Clin Immunol 1999; 104:705.
  6. Engler RJ. Mosquito bite pathogenesis in necrotic skin reactors. Curr Opin Allergy Clin Immunol 2001; 1:349.
  7. McCormack DR, Salata KF, Hershey JN, et al. Mosquito bite anaphylaxis: immunotherapy with whole body extracts. Ann Allergy Asthma Immunol 1995; 74:39.
  8. Peng Z, Simons FE. A prospective study of naturally acquired sensitization and subsequent desensitization to mosquito bites and concurrent antibody responses. J Allergy Clin Immunol 1998; 101:284.
  9. Palosuo K, Brummer-Korvenkontio H, Mikkola J, et al. Seasonal increase in human IgE and IgG4 antisaliva antibodies to Aedes mosquito bites. Int Arch Allergy Immunol 1997; 114:367.
  10. Peng Z, Rasic N, Liu Y, Simons FE. Mosquito saliva-specific IgE and IgG antibodies in 1059 blood donors. J Allergy Clin Immunol 2002; 110:816.
  11. Peng Z, Simons FE. Comparison of proteins, IgE, and IgG binding antigens, and skin reactivity in commercial and laboratory-made mosquito extracts. Ann Allergy Asthma Immunol 1996; 77:371.
  12. Wang Q, Beckett A, Simons FE, Peng Z. Comparision of the mosquito saliva-capture enzyme-linked immunosorbent assay and the unicap test in the diagnosis of mosquito allergy. Ann Allergy Asthma Immunol 2007; 99:199.
  13. Katz TM, Miller JH, Hebert AA. Insect repellents: historical perspectives and new developments. J Am Acad Dermatol 2008; 58:865.
  14. Cohen B, Hebert AA. Assault of the arthropods. Which product should you recommend to prevent insect bites? AAP News 2011; (April):15. www.aapnews.org (Accessed on June 09, 2011).
  15. Karppinen A, Kautiainen H, Petman L, et al. Comparison of cetirizine, ebastine and loratadine in the treatment of immediate mosquito-bite allergy. Allergy 2002; 57:534.
  16. Karppinen A, Brummer-Korvenkontio H, Petman L, et al. Levocetirizine for treatment of immediate and delayed mosquito bite reactions. Acta Derm Venereol 2006; 86:329.
  17. Karppinen A, Brummer-Korvenkontio H, Reunala T, Izquierdo I. Rupatadine 10 mg in the treatment of immediate mosquito-bite allergy. J Eur Acad Dermatol Venereol 2012; 26:919.
  18. Golden DB, Moffitt J, Nicklas RA, et al. Stinging insect hypersensitivity: a practice parameter update 2011. J Allergy Clin Immunol 2011; 127:852.