The great majority of insect allergic animals just have a simple allergic response – a reaction local to the sting site which appears as just a swelling arising from the release of histamine and other chemicals from the body tissues near to the sting site.
Mosquito allergy may result in a collection of symptoms called skeeter syndrome that occur after a bite.
It is estimated that 5-10% of individuals will experience a generalized systemic reaction that can involve symptoms ranging from hives to wheezing and even anaphylaxis.
[1] In the United States approximately 40 people die each year from anaphylaxis due to stinging insect allergy.
[5] A 2012 meta-analysis found that venom immunotherapy is an effective prophylactic treatment against insect bite and sting allergic reactions, and significantly improves the quality of life of people affected by severe insect allergies.