Why Do Mosquitoes Bite Some People More Than Others?
Why Do Mosquitoes Bite Some People More Than Others?
Some people attract far more mosquito bites than others, and the reasons are rooted in genetics, body chemistry, and behaviour. Professor Caitriona Ryan, Consultant Dermatologist at the Institute of Dermatologists and Clinical Professor at UCD, explains the key factors and what you can do to reduce your risk.
Speaking on Newstalk Breakfast with Anton Savage, Professor Caitriona Ryan, Consultant Dermatologist at the Institute of Dermatologists and Clinical Professor at UCD, explained the science behind why some people seem to attract far more mosquito bites than others.
Does Blood Type Affect How Often You Are Bitten?
According to Professor Ryan, several genetic and physiological factors influence how attractive a person is to mosquitoes. People with blood type O are bitten roughly twice as often as those with blood type A, and higher carbon dioxide output, more common in larger adults and during pregnancy, also increases attractiveness. Children, by contrast, tend to be bitten less often because they produce less CO2.
"People with blood type O are bitten roughly twice as often as those with blood type A."
Professor Caitriona Ryan, Institute of Dermatologists
Do Body Temperature, Sweat, and Clothing Colour Make a Difference?
Body temperature and sweat play a role too. Mosquitoes are highly effective at detecting sweat, which means exercising, or simply being active in warm conditions, can make a person more noticeable. Even a single alcoholic drink was noted as a factor, with changes in sweat composition after drinking increasing attractiveness to mosquitoes. Clothing colour matters as well: mosquitoes are drawn to high visibility colours, so paler clothing offers some natural protection.
How Can You Protect Yourself from Mosquito Bites?
On prevention, Professor Ryan recommended the basics: keeping windows and doors closed at night, since even a small gap is enough for mosquitoes to get in, and using an insect repellent containing DEET. She advised caution with high concentration DEET products applied directly to skin, particularly for children, and suggested applying repellent to clothing rather than skin where possible. Citronella bracelets were also mentioned as a helpful, lower intervention option.
What Should You Do If You Have a Strong Reaction to Mosquito Bites?
For anyone prone to a strong reaction, swelling, itching, or discomfort at the bite site, Professor Ryan's advice was to travel with hydrocortisone or a topical steroid to reduce swelling, and to consider taking an antihistamine for the duration of a trip if reactions have previously been severe enough to disrupt sleep or daily activities.
Many thanks to Anton Savage and the team at Newstalk Breakfast for having Professor Ryan on to share this insight.
Read more skin health guidance from Professor Caitriona Ryan and the team on our blog.
Listen back to the interview here:
https://www.newstalk.com/podcasts/highlights-from-newstalk-breakfast/are-you-a-mosquito-magnet
Frequently Asked Questions
Why do mosquitoes bite some people more than others?
Mosquitoes are attracted by a combination of factors including blood type, carbon dioxide output, body temperature, sweat composition, and clothing colour. People with blood type O and those who produce more CO2 tend to be bitten more frequently.
Does blood type affect mosquito bites?
Yes. Research suggests people with blood type O are bitten approximately twice as often as those with blood type A. Blood type influences the chemical signals released through the skin that mosquitoes detect.
Does alcohol make you more attractive to mosquitoes?
Even a single alcoholic drink can alter sweat composition in ways that increase attractiveness to mosquitoes, according to Professor Caitriona Ryan of the Institute of Dermatologists.
What is the most effective mosquito repellent?
Insect repellents containing DEET are among the most effective options. Professor Ryan advises applying repellent to clothing rather than directly to skin, particularly for children, and using lower concentrations where possible.
What should I do if I have a severe reaction to a mosquito bite?
If you experience significant swelling, itching, or discomfort, a topical steroid or hydrocortisone can help reduce inflammation. An antihistamine taken for the duration of travel may also be appropriate if reactions have previously disrupted sleep or daily activities. Speak to a healthcare professional for personalised advice.
