Female mosquitoes need blood to lay eggs. When they land on your skin in search of yours, they inject saliva that contains proteins using “little serrated blades in the proboscis” – their needle-like mouths – “that drill down into your skin,” said Dr Allison Gardner, an associate professor at the University of Maine who studies the management of infectious diseases from ticks and mosquitoes. Those proteins not only numb the skin but dilate blood vessels to make feeding more efficient.
In response, your body releases histamine as an immune response to the saliva. That histamine is the reason for itching and swelling, a signal to your brain to investigate.
Can’t I just scratch it?
You can. It’s almost impossible not to. “When we scratch, we distract the brain from the itch with another sensation, a mild pain,” said Dr Lyda Cuervo Pardo, an immunologist and associate professor at the University of Florida. “Our brains release serotonin, and we feel better.”
This is the same reason the fingernail tactic, a hot spoon or the shock of a cooling spray provides relief. “Itch, pain, tickling sensations and temperature all travel on the same neural highway, so to speak,” said Dr Heather Goff, an associate professor of dermatology at UT Southwestern in Dallas. “When you flood that highway with other traffic, you override the itch.”
Cuervo Pardo said you can get stuck in an “itch-scratch cycle”. The mild pain from scratching overrides the itch and tells your brain to release serotonin, a natural pain reliever. But serotonin can also amplify the itch signals, making you scratch more. When your skin is damaged from overzealous scratching, your body again responds with more histamine, leaving you in a miserable loop, said Dr Cosby Stone, an allergist and assistant professor at Vanderbilt University.
What’s a better option?
Try an ice pack, cooling spray or even a menthol ointment such as Vicks VapoRub for a lingering tingly effect. A cooling agent layered with hydrocortisone will best soothe the itch in the short and long term. As for what cooling product to use, “anything that feels good” will work, Stone said. “You trick your brain into not noticing the itch, and cooling agents also cause the blood vessels to constrict, which helps with swelling.”
A cold washcloth could also provide some welcome, gentle friction, Stone said, and a Band-Aid can help ingredients penetrate the skin and keep your fingernails away, an especially helpful trick for children.
Antihistamine pills such are more effective than topical creams, as they calm the body’s overall immune response. You can even take an oral antihistamine in preparation for a camping trip or every day of the summer, if you want. “Having histamine blockers already in your system will mean less of a reaction, period,” said Stone.
What about other gimmicks?
If you prefer hot to cold, Goff said a heat pack or warm washcloth can override the itch sensation in the same way a cooling product can. But she does not recommend a hot spoon, which could cause a minor burn.
She’s more sceptical about suction tools. “The amount of saliva a mosquito injects and the hole it makes are both microscopic. I can’t imagine there’s even a physical hole to suck something out of,” she said. That said, the sucking sensation serves as a mildly uncomfortable distraction in the same way a fingernail does – at least to me and my 6-year-old, who tried it on our own bites.
A better use of your time and money might be avoiding mosquito bites in the first place. Use an insect repellent and consider wearing long sleeves and pants while outside. Gardner, who uses aloe and hydrocortisone to treat her own bites, wears a thin net over her hat to cover her face when she’s hiking or entering a mosquito habitat.
“It might not be a good fashion statement,” she said, “but it definitely helps.”
This article originally appeared in the New York Times.
Written by: Elizabeth Passarella.
©2024 THE NEW YORK TIMES
