Why Mosquito Bites Itch, and What Really Helps

Mosquito bites can become intensely itchy, but not every home remedy works. In an explainer on how to relieve the redness, swelling, and itching, dermatologist Dr. Rajani Katta of Blair, Texas, says the reaction is actually an allergy to mosquito saliva. When an adult mosquito bites, it injects saliva into the skin, and the immune system reacts to the proteins in it. Some people react more strongly than others, which is why some bites become red, raised, and very itchy while others remain small bumps.

Katta says the first-line treatment is usually 1% hydrocortisone cream, applied twice a day. She says it helps calm inflammation and reduce redness, swelling, and itching. But she warns not to use it on the face for more than a month, because steroids can thin the skin and make delicate areas, such as the eyelids, more vulnerable to cuts and bruises.

If hydrocortisone is not available, Mayo Clinic recommends calamine lotion or a paste made from baking soda and water. A cold compress or a cool, damp cloth can also ease severe itching. By contrast, Katta says common folk remedies like witch hazel, lemon juice, and apple cider vinegar may irritate the skin, increase inflammation, and worsen redness.

For quick relief, she suggests lightly tapping or pressing on the bite, since that can distract the nerve signal carrying the itch sensation to the brain. Scratching should be avoided because open wounds raise the risk of infection and can also lead to lasting dark marks or scars. To prevent bites in the first place, people should use insect repellent, wear long sleeves and pants, and consider citronella candles or thermal bug lamps outdoors. The article notes that these precautions help not only against itching, but also against diseases mosquitoes can spread, including Zika and West Nile virus.