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Mosquitoes are small flying insects. Female mosquitoes have a long, piercing mouthpiece, with which they pierce the skin to consume their blood. Some mosquito bites are harmless, but others carry dangerous diseases.

It is only female mosquitos that bite people. Blood serves as a source of protein for their eggs. Male mosquitoes do not consume blood.

Mosquito bites pose a considerable health risk, with mosquito-borne diseases causing millions of deaths a year worldwide. Malaria, one of the most commonly known diseases unique to mosquitos, killed around 438,000 people globally in 2015.

However, a person can take preventive measures to keep them at bay. This article explores the symptoms and risks, as well as how to avoid bites.

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A mosquito bite might lead to a severe infection.

Symptoms of a mosquito bite occur shortly after being bitten. A round, red bump with a dot in the middle usually accompanies an itching sensation.

Other signs of a mosquito bite include:

  • dark spots that resemble bruising
  • swelling or redness
  • small blisters in place of hard bumps

Multiple bumps are also common. These indicate that a mosquito pierced the skin in more than one location, or that more than one insect bit the person.

Children and people with weakened immune systems can experience extra symptoms, such as hives, swollen glands, and low-grade fever.

In general, symptoms become less severe with additional bites. This is because the body slowly acclimatizes to the bites.

According to the American Academy of Allergy, Asthma, & Immunology (AAAAI), a mosquito bite might cause anaphylaxis in rare cases. This is a potentially life-threatening condition that causes throat swelling, hives, faintness, or wheezing.

Anaphylaxis requires immediate medical attention.

The risk of developing a serious disease is the most dangerous outcome of a mosquito bite.

There are several harmful infections that mosquitoes can carry and transmit, including:

  • Malaria: Parasites cause this life-threatening disease by infecting and destroying red blood cells. To control and treat malaria, early diagnosis is crucial.
  • West Nile virus: Most people with West Nile Virus show no symptoms, although some develop a fever or other flu-like symptoms. For a small number of people with the virus, a serious illness develops in the nervous system.
  • Zika virus: This is a generally mild condition that initially causes fever, joint pain, and rash. The initial symptoms of Zika usually pass after 1 week, but the disease can lead to congenital anomalies if a woman becomes pregnant after receiving a mosquito bite.
  • Yellow fever: This virus causes inflammation in the brain and spinal cord. Its symptoms include fever and sore throat.
  • Dengue fever: This disease can trigger high fever, rash, muscle soreness, and joint pain. In the most extreme cases, severe bleeding, shock, and death can occur. Dengue fever is mostly active in tropical and sub-tropical regions.
  • Chikungunya: Joint pain, headache, rash, and fever are common in chikungunya. People with the disease require bed rest and fluids for recovery.

If a person notices a mosquito bite and feels any flu-like symptoms or a fever, they should seek medical treatment immediately.

Female mosquitoes tend to target some people over others when it comes to feeding. Researchers do not yet fully understand the reasons for this selective process.

One 2013 study noted that mosquitos have sensors that pick up on carbon dioxide emissions and body odor. They can then identify which nearby people would make a suitable feeding ground.

Body heat, movement, and body odors, such as sweat and lactic acid, might also play a role in attracting mosquitoes.

Prevention

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Repellent is an effective method for keeping mosquitos at bay.

Preventing mosquito bites is always more effective than trying to treat them, given the potential seriousness of the diseases that can transmit during the bite.

The Environmental Protection Agency (EPA) advise that mosquitoes need water to breed. Removing sources of standing water around the home and garden can reduce the number of mosquitoes in the area.

The following steps can help prevent bites:

  • Use screens and netting.
  • Cover up the skin when outdoors.
  • Avoiding wooded and grassy areas.
  • When planning to be in mosquito-dense areas, avoid bright clothing, perfumes, and scented beauty products.

Repellents

Using insect repellent may be necessary when doing activities that naturally increase carbon dioxide emissions and bodily odors, such as exercising outdoors.

The Centers for Disease Control and Prevention (CDC) recommends a number of effective options for repelling mosquitos.

DEET

N,N-Diethyl-meta-Toluamide (DEET) is one of the most commonly used chemical-based mosquito repellents. Studies show that it is one of the most effective on the market.

DEET works by interfering with the receptors in the mosquito that detect carbon dioxide and body odor, causing them to not detect the person wearing DEET as a potential source of nutrition.

According to the U.S. Environmental Protection Agency (EPA), DEET provides protection against mosquito bites for between 2 and 12 hours, depending on the percentage of DEET in the product.

DEET is available in various forms, including liquids, sprays, lotions, and wristbands.

Always follow the directions on the label when using DEET products.

Picaridin

Picaridin is a newer type of insect repellent. Working in the same way as DEET, it prevents the mosquito from recognizing its prey.

A 2018 meta-analysis shows that the preventive effects of picaridin last for more or less the same amount of time as DEET.

Picaridin is a safe option for children under 6 months of age, as it contains fewer potentially toxic qualities than DEET.

Oil of lemon eucalyptus

Oil of lemon eucalyptus may be a good option for those who prefer a natural, chemical-free repellent.

Repel and Off! Botanicals are examples of products that contain this natural oil.

Travel advice

People who are planning a vacation should learn about the risk of mosquito-borne illness at their intended destination.

They should also speak with a healthcare provider before traveling. There may be optional or mandatory vaccinations or medications available to protect against certain mosquito-borne diseases, such as yellow fever or malaria.

Remember also to pack an effective insect repellent.

Where possible, choose accommodation with air conditioning or window and door screens, or sleep under a mosquito bed net.

Female mosquitos bite humans to consume blood. In doing so, they cause irritation and swelling but can also transmit some extremely harmful and sometimes fatal diseases.

They can also cause harmful allergic reactions in some people.

Malaria, dengue fever, and yellow fever are only a few mosquito-borne conditions. Preventing mosquito bites can be a matter of life-and-death in areas where these conditions are prevalent.

There are a few effective options for repellent sprays, including DEET, picaridin, and oil of lemon eucalyptus. Antihistamine and hydrocortisone creams can help soothe swelling.

It is vital to prepare for travel to mosquito-heavy areas with the appropriate vaccinations. Seek urgent medical attention if a bite occurs and a widespread rash, fever, and headache develop.

Q:

A mosquito has just bitten me. What immediate steps should I take?

A:

An initial first step is to apply or reapply a mosquito repellent, covering any potentially exposed skin. This measure ensures that no further bites occur. Another way to achieve this is by setting up a physical barrier, such as mosquito netting or simply returning indoors.

Once you have applied protection, you may then begin to treat the bite area with ice or a hydrocortisone cream. Itching will probably continue, but do your best to not scratch the bite, as this will cause further irritation.

Finally, take note of your location as well as any symptoms of illness, such as fever, joint pain, or headache. This is to make sure you have not contracted an infection.

Debra Sullivan, PhD, MSN, RN, CNE, COI Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.