The simple trick that can stop a mosquito bite from itching

It’s hard to think about much else when you have a fresh mosquito bite you’re desperate to scratch.

The insatiable itch, the swollen red bump — it can even be uncomfortable enough to keep you up at night. While you can’t do much to make the bite go away faster, there are ways to relieve itch in the meantime — and prevent you from scratching so hard that you break the skin and risk an infection.

One unexpected method: applying concentrated (though not too hot) heat or something cold on your mosquito bite, a technique that “could inhibit the feeling of itch,” said Gil Yosipovitch, a professor and director of the Miami Itch Center at the University of Miami.

Here’s why it might work and how to try it safely.

When a mosquito pierces the skin, it injects saliva, which contains proteins that prevent blood clotting, said Shawn Kwatra, chair in the department of dermatology at the University of Maryland School of Medicine and director of the Maryland Itch Center.

“It’s these saliva proteins that trigger a reaction,” he explained. “Within the first hour of the bite, the area may become more swollen, red, warm and itchier.”

For some people, this reaction can be even more dramatic. “In highly sensitive people, the system recognizes those proteins more strongly and releases larger amounts of histamine and other inflammatory chemicals,” resulting in more significant swelling and redness, said Kwatra. But even mild reactions can be uncomfortably itchy as they heal, which can take anywhere from hours to days.

Heat might help relieve mosquito bite itch because it’s essentially a distraction, said Ethan Lerner, an associate professor of dermatology at Harvard Medical School.

The theory, explained Kwatra, is that a change in temperature may help interrupt nerve and inflammation signals that cause that itchy feeling. “Heat activates temperature-sensitive receptors in the skin,” he said. “Stimulating these pathways may temporarily override or dampen each signal similarly to how rubbing a bump can briefly distract from itch.”

In other words: “It’s kind of averting the nervous system from one sensation to another,” said Yosipovitch.

Applying something cold may relieve itch using a similar process, experts said, and cold temperatures also have the benefit of helping to reduce inflammation. “Cold can slow itch nerve signaling, constrict blood vessels, calm inflammation and can help numb the area,” said Kwatra.

There’s not a lot of research on the topic, but the studies that do exist are promising.

A 2022 review article that Yosipovitch co-wrote on mosquito bite reactions identified cold compresses as a topical treatment option. Researchers noted that cold may help by activating something called the TRPM8 receptor, a sensor on nerve cells that’s activated by cold temperatures and cooling compounds such as menthol.

In 2023, researchers looked at the efficacy of a smartphone-controlled medical device that emitted heat and found that mosquito bite-induced itch decreased by 57 percent within the first minute of treatment and by 81 percent within 10 minutes. Because participants reported rapid itch reduction, this suggests the relief “is working through nerve signaling rather than slower anti-inflammatory pathways,” noted Kwatra. (This study “was a bit flawed,” said Yosipovitch, since users of the device were invited to join the study, so “it’s not a real control,” he said.)

A randomized clinical trial published the following year investigated a thermo-therapeutic heat pen that was similarly designed to relieve mosquito bite itch. Participants who used the product reported significantly reduced itching within one minute of treatment compared with those who had a placebo device.

Applying heat on a mosquito bite may temporarily distract from the itch, but it shouldn’t be hot enough to burn your skin. “Use brief, mild, localized warmth,” said Kwatra, “so potentially a warm washcloth.”

Other options include running a metal spoon under warm water, or applying a reusable warm gel pack or heating pad on low, Kwatra said. “I would avoid a hair dryer because it’s harder to control the temperature and can overheat skin quickly.”

However, if you’re someone who tends to experience one of those bigger, more dramatic reactions from a mosquito bite or even has an allergy — in which case you might develop significant inflammation and swelling after a bite — heat may not be the best option, cautioned Yosipovitch.

Heat “could maybe work for some folks,” he said. But because warmth can also increase blood flow, “heat itself can actually sometimes lead to more itch,” which could be especially irritating for people who are already more sensitive to mosquito bites, he said.

Applying something cool may be a safer first option in this case, said Kwatra: You might wrap an ice pack in a thin cloth, or use a cool, wet washcloth or chilled gel pack as a cold compress on the bite for about 10 minutes.

For mild mosquito bites, there are other strategies to ease the itch:

A more severe reaction from any insect bite warrants a call to your medical provider, especially if you’re experiencing symptoms such as significant swelling, hives, swollen lymph nodes or a low-grade fever, which may be signs of an allergic reaction.