I’ve lived in Florida my whole life and had tons of mosquito bites, but now they are swelling way more and lasting a week or longer.  What’s up with that? 

It means it’s time for you to leave Florida and lessen our traffic jams….no, just kidding.  Most likely it means you have developed an allergy, but a rare cause for strong reactions to arthropod bites is as an early sign of leukemia or myeloma.   

Mosquitos have been around for over 100 million years (specimens found in amber date to 100 million years ago).  Homo sapiens are a new addition to the planet.  Scientists estimate that there have been 110 billion humans and that half of us have died from mosquito borne diseases.   

A few additional facts about mosquitos are cogent.  Only female mosquitos bite.  They need blood to nourish their eggs and larvae.  Male mosquitos eat pollen.  When a mosquito bites us, she uses six mouth parts.  There are two serrated “knives” that cut our skin, then two “retractors” to open the rent and one retractable “sucking needle” to extract blood and one “saliva needle” to insert the saliva.   And the saliva she injects as an anti-coagulant contains proteins that can lead to the development of allergy.  In experimental models, the best way to induce an allergic reaction to a substance is by discreet but intermittent exposure.  So, if that is what has happened to you over time, your immune system has “learned” to dislike the salivary protein.  Depending on the severity of the reaction, various therapies can be used.  Oral antihistamines help.  Topical steroid (either OTC or prescription) applied quickly and under occlusion (a band aid makes the steroid penetrate better) works even better.  For more severe cases an allergy shot for mosquito can be done.   

On a different note, in terms of mosquito borne diseases, malaria has garnered the most attention.  Several standard types of vaccine strategies have been tried with modest and mixed results.  More recent trials with a monoclonal antibody are looking much more promising.   

Mosquitos do bite some individuals more than others.  Women are more attractive to mosquitos than men.  Pregnant women even more so, as during pregnancy women exhale 20% greater carbon dioxide than non-pregnant women.  Mosquitos are attracted by carbon dioxide, type O blood, scents/perfumes, certain skin bacteria and bright clothing.  Beer also seems to attract them.