Skip to main content

The Globe and Mail

How do I deal with itchy, swollen bug bites?

Stock photo/Thinkstock

The question

I went to my friend's cottage and was eaten alive by black flies. Some of the bites have gotten really swollen and turned red, and they are incredibly itchy. Is there anything I can do to stop the itch?

The answer

Story continues below advertisement

Itchy bites are bothersome and can really put a damper on being outdoors and enjoying the summer. Thankfully, there are some simple steps you can take to ease the itch and take care of these common bites.

Most people have some skin reaction after an insect bite. For some, bites can result in mild swelling and itch that resolves within a day or two. For others, a persistent itch can occur that can be unbearable.

To be able to get to the root of the issue, let's understand how the itch starts.

When an insect bites the skin, venom or an irritant (specific to the insect) is released at the site. Our immune system recognizes this foreign irritant and releases a substance found in the body called histamine. This triggers an inflammatory reaction that causes blood vessels to enlarge near the bite area, which results in swelling. Histamine and the swelling both irritate nerve endings in the skin, which makes us itch.

To reduce the itch, try the following steps:

  • Apply a cold pack or ice wrapped in cloth to reduce swelling to help lessen irritation to the nerve endings in the skin.
  • Apply cream such as AfterBite, calamine lotion or baking soda mixed with water to calm itchy skin. If your whole body is itchy, consider a cool bath with Epsom salts.
  • Consider a topical treatment such as hydrocortisone cream directly on the bite. This will work to decrease inflammation and that itchy sensation.

If topical therapies don't work, try an over-the-counter antihistamine (such as Benadryl or Reactine) that can decrease swelling and reduce irritation. Be aware that these can cause drowsiness, so try the daytime formulations unless used before bedtime. If the itch is still unbearable, a visit to your doctor may be necessary for a stronger antihistamine that must be prescribed.

If your itch or pain worsens or redness increases in the area or if there is any yellow drainage from the bite site, get checked out by a doctor. These can all be signs of an infection that may require treatment with antibiotics.

Story continues below advertisement

While the vast majority of bites are mild and resolve on their own, if you develop a rash, painful joints, fever or any difficulty breathing, this could be a sign of a serious allergy and needs immediate attention.

Remember, the best protection against insect bites is prevention. When you're outdoors, wear clothing that covers up your skin and apply insect repellent, especially if you're visiting areas with high levels of bite incidence. Taking these precautions and treating itchy bites when they do occur can help you enjoy the outdoors and fully take advantage of our summer months.

Send family doctor Sheila Wijayasingheyour questions at She will answer select questions, which could appear in The Globe and Mail and/or on The Globe and Mail web site. Your name will not be published if your question is chosen.

The content provided in The Globe and Mail's Ask a Health Expert centre is for information purposes only and is neither intended to be relied upon nor to be a substitute for professional medical advice, diagnosis or treatment.

Report an error Editorial code of conduct
As of December 20, 2017, we have temporarily removed commenting from our articles. We hope to have this resolved by the end of January 2018. Thank you for your patience. If you are looking to give feedback on our new site, please send it along to If you want to write a letter to the editor, please forward to