Understanding mosquito bites: Why you’re a target, why they itch
ILLUSTRATION Ed Lustan
MANILA, Philippines—Aside from cold and flu, one of the common ailments to look out for this rainy season—especially among people who are mosquito magnets—are mosquito bites, which cause itchy, swollen bumps on the skin and in worse cases, life-threatening diseases.
Mosquito bites are known to cause serious—and often fatal—diseases such as dengue, malaria, Zika virus, West Nile virus, chikungunya, and filariasis.
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However, in most cases, mosquito bites do not cause any lasting and life-threatening harm. Instead, these simply cause short-term irritation and annoyance—leaving itchy red bumps on the skin.
Health experts and studies also found that some people tend to get more mosquito bites than others due to several reasons.
In this article, INQURER.net will try to provide more detail about mosquito bites—what makes them itchy and why scratching them is not the best response—and what makes other people more delectable for mosquitoes.
Some attract mosquitoes more than others
In a recently published study, American neuroscientist Leslie Vosshall—lead researcher and Howard Hughes Medical Institute’s vice president and chief scientific officer—found that female aedes aegypti mosquitoes—also known as dengue virus-carrying mosquitoes—pick their prey based on a cocktail of body odor, carbon dioxide, and heat.
“Mosquitoes are intensely attracted to human-emitted body odor, heat, and carbon dioxide, which they detect using three different large multi-gene families encoding odor-gated ion channels,” the study noted.
GRAPHIC Ed Lustan
Vosshall and her colleagues also teamed up with scientists at the Swedish University of Agricultural Sciences and discovered that mosquitoes can detect different smells and different “flavors of body odor”—including a perfumy smell and stinky foot odor.
Perfumes and other scented body products, according to the US health institution Cleveland Clinic, signal to mosquitoes that a human target is within striking distance. Scented body products, including lotions, deodorants, and fragrances—especially those with strong floral scents—attract the blood-dining mosquitoes.
“Mosquitoes are attracted to our body odor, but they also are attracted to the things we use to mask body odor,” said American dermatologist Jennifer Lucas.
Some products also contain lactic acid, which could also attract mosquitoes.
“Some of the products we use for rejuvenating purposes have alpha hydroxy acids in them, which is an attractant to mosquitoes,” Lucas added.
Cleveland Clinic also cited several factors which might prompt mosquito bites, such as:
- wearing dark-colored clothing;
- having high body temperature;
- visiting a region with active mosquito-transmitted diseases
- spending time near stagnant water.
It has also been said that certain food and drinks could also make people more appetizing to mosquitoes. Potassium-rich foods as well as salty, spicy, or sweet snacks can attract mosquitoes.
GRAPHIC Ed Lustan
Cleveland Clinic noted that there has not been any research done to support those claims, though.
However, previous studies found that beer and bananas can increase the likelihood that mosquitoes will follow people around and increase the risk of mosquito bites.
Another huge factor pointed out by scientists as one of the reasons some people attract mosquitoes more than others—also referred to as “mosquito magnets”—is genetics and blood type.
The American Mosquito Control Association (AMCA), said carbon dioxide is “the most universally recognized mosquito attractant” and can draw mosquitoes from up to 35 meters.
“When female mosquitoes sense carbon dioxide they usually adopt a zigzagging flight path within the plume to locate its source. Once in the general vicinity of a potential host, other cues predominate, including body odors (sweat, lactic acid, etc.) and heat,” AMCA explained.
High concentrations of steroids or cholesterol on a person’s skin as well as excess amounts of uric, lactic acid, and ammonia acid can also trigger a mosquito’s sense of smell.
Past studies have shown that people with blood type O attract mosquitoes more than those with other blood types.
Certain activities such as hiking, camping, working with animals, and visiting farms and forested areas also increase the chance of getting mosquito bites.
Why does it itch?
One of the most commonly asked questions about mosquito bites is why it causes that itchy feeling.
According to the US Centers for Disease Control and Prevention (CDC), the bite itself is not what causes itchiness and the swollen, red bumps on the skin.
“When a mosquito bites you, it pierces the skin using a special mouthpart (proboscis) to suck up blood. As the mosquito is feeding, it injects saliva into your skin,” the US CDC explained.
The body registers the saliva, which is secreted to the bloodstream, as an allergen. The immune system then reacts and releases histamine to fight off and remove the allergen from the body—which, as a result, causes itching and bumps in the skin.
Stop scratching!
As tempting as it is to scratch mosquito bites, health experts strongly advise not to scratch the bumps as it could cause further health issues.
Scratching mosquito bites can make it more irritated and inflamed and could lead to bacterial infections such as cellulitis.
“The bacteria can infect the deeper layers of your skin if it’s broken, for example, because of an insect bite or cut, or if it’s cracked and dry,” the National Health Service (NHS UK) said on its website.
Among the warning signs related to infected mosquito bites include:
- swelling of the lymph nodes
- redness around the mosquito bite
- red streaking that extends beyond the mosquito bite
- pus or drainage
- the area feels warm to touch
- chills
- fever (above 37.7 ℃ or 100 degrees ℉)
GRAPHIC Ed Lustan
The US CDC advised contacting a doctor or a health care provider in case of severe reactions to a mosquito bite, such as:
- fever
- headache
- body ache
- signs of infection
- serious allergic reactions (hives, trouble breathing, changes in skin color or texture, painful blisters)
Avoid mosquito bites
While there are already several initiatives done in communities and many countries to eradicate blood-sucking, disease-carrying mosquitoes, there are many ways individuals can do to prevent mosquito bites.
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People can limit exposure to mosquitoes by avoiding outdoor activities when mosquitoes are most active—usually from dusk to dawn. Installing screens on windows, doors and camping gear as well as using mosquito netting over strollers, cribs, or when sleeping outdoors can also help.
Health experts also suggest using insect repellents that contain active ingredients DEET or picaridin, which have been found to provide the best protection.
Covering up using protective clothing and gear—such as long sleeves, socks, closed-toe shoes, long pants, light-colored clothes, and hats—can also help prevent mosquito bites.
Certain medications, such as nonprescription antihistamines, also help prevent severe reactions to mosquito bites.
To reduce mosquitoes around your home, the Department of Health (DOH) has been actively encouraging local government units (LGU) and the public to follow some preventive measures.
One of these is the 4 o’clock habit where communities are urged to search and destroy or overturn containers or areas which attract mosquitoes.
The health department reminded the public to always remember the 4S:
- Search and destroy mosquito breeding places.
- Self-protection.
- Seek early consultation.
- Support fogging or spraying in areas with a recorded increase in cases for two consecutive weeks to prevent an impending outbreak.
