Mosquito bites are characterized by an itchy, inflamed bump that forms a few minutes after the bite. The bump may become red, hard, swollen, and itchier over time. In some cases, a large, swollen, inflamed area or a hive-like rash may develop around the bite. These reactions are sometimes called "skeeter syndrome" and are more common in children.
Mosquito bites are caused by female mosquitoes feeding on your blood. As they feed, they inject saliva into your skin, which triggers an immune system reaction that results in the itchy bump. Mosquitoes are attracted to smells, such as those from sweat, floral scents, and exhaled carbon dioxide.
Scratching mosquito bites can lead to infection. Additionally, mosquitoes can carry the viruses that cause certain diseases, such as West Nile virus, Zika virus, and the viruses that cause malaria, yellow fever, and some types of brain infection. These viruses are transmitted to humans when an infected mosquito bites them and injects the virus-laden saliva into their bloodstream.
To prevent mosquito bites, it is recommended to limit exposure to mosquitoes by repairing any tears in screens on windows, doors, and camping gear, using mosquito netting over strollers and cribs, and using mosquito netting when sleeping outdoors. The most effective insect repellents in the United States include DEET, icaridin, oil of lemon eucalyptus, IR3535, para-menthane-diol (PMD), and 2-Undecanone. These ingredients temporarily repel mosquitoes and may offer longer-lasting protection. It is important to read the label before applying any repellent and to follow the instructions carefully.
If someone continues to scratch either mosquito or bed bug bites and does not keep the bite clean and medicated, there is a risk of a secondary infection. If more severe symptoms develop after a bite, such as an allergic reaction, fever, headache, or body aches, it is important to see a healthcare provider. Treatment will vary depending on the type and severity of the infection.