Dealing with extreme allergic reactions to mosquito bites

I’ve had some pretty bad allergic reactions to some bitey insects while I’ve been in Rio. I’ve had reactions before, but not as bad as here. For instance, while I was in Sevilla in last year, I was bitten a few times, and my hand swelled up, and tiny blisters formed, and I got some tiny blisters on my arms when I was in the Maldives too.  But this time, when I was bitten on my feet and ankles, the reaction was much worse, which blisters becoming bullae up to 2cm (1in) across, and almost semi-spherical in size. My feet also swelled up to a size that made me think of bloaty-head from Theme Hospital. I’ll save you pictures, but you can search Google if you’re morbidly curious. We’ve not sure why they seem worse on my legs than on my arms or face. Maybe gravity is a cause of the welling of fluid in my legs and feet.

I’ve discovered that the reason for the reaction is that when mosquitoes bite you, they inject a tiny amount of a protein into your body, and it’s this protein that you’re allergic to.

Remember that I am not a trained medical professional and you should seek medical advice rather than following something you read on the Internet.

So, after a little bit of trial and error, here’s my guide to reducing the impact of bites:

What you will need

My bite care kit contains:

  • Hydrocortisone cream – To reduce itching
  • Anti-histamine tablets – To reduce affects of the reaction
  • Ibuprofen – (Optional) to reduce swelling and pain
  • Gauze – To cover bite
  • Medical tape – To hold down the gauze
  • Antiseptic spray
  • Anti-mosquito spray

As soon as you notice a bite:

The first thing you should do is to cover the area with a tiny amount of hydrocortisone cream, which will reduce the itching. I’ve noticed that the more the area is hassled, the bigger the reaction tends to be, so reducing the itching will not only reduce the amount it bothers you, but also improves the appearance of the reaction. You should also take an antihistamine tablet to reduce the reaction.

You should be very careful with the hydrocortisone cream, using it very sparingly and no more than for three days on the same spot. It’s also highly recommended to not use the cream on your face. One of the affects of cortisone steroids is to reduce the thickness of your skin, which can cause further problems if used long-term. The reason for not using it on your face is that the skin on your face is more delicate than other places, and it’s possible for the cream to cause adverse reactions, which are far more prominent on your face. It can also make a few skin conditions, like acne, worse. You can read further advice about using it on your face on the NHS’s website.

As soon as you notice blisters forming:

This part goes against most of the advice I’ve seen on-line from medical resources. I’m going to advocate popping the blisters as soon as you see them forming. The reason this is recommended against, is because breaking the skin can dramatically increase the chance of infection, which the skin will form a barrier against. The choice as to whether you want to risk this is up to you, but with proper care, I’ve not found a problem. A few of my blisters have popped accidentally anyway, and when they’re larger, the protective skin can easily split and reveal raw skin underneath.

Before you pop the blisters, spray the area with the antiseptic spray. You’ll often notice several tiny blisters forming around the bite, and often not actually on the site of the bite itself. Make sure you pop each of the biggest blisters you can see. Left alone, these tiny blisters will grow and merge into one single large blister, filled with liquid.

The sooner you pop the blisters, the smaller the effect of the blisters will be.

The downside to popping the blisters is that the liquid that was going to fill the blisters is still going to be produced and still has to go somewhere. And that somewhere is to seep out of you. The liquid will be a clear, odourless, yellowly-brown colour. If it smells or is not clear, then there’s a chance it’s infected and you should contact your doctor as soon as possible.  

Once you’ve popped all the blisters, remove the excess liquid by pressing a clean tissue against them and spray some more anti-septic spray on the area, and use the tissue again to remove any excess spray from the surrounding area where you will be taping the gauze to yourself, but leave it on the bite itself.   Take the gauze and fold it in half once or twice depending on the size of the gauze and the area you need to cover, and the use the medical tape to tape it down. Tape across the top and bottom, with excess tape past the gauze, and do the same with the sides. You should end up with something looking a bit like a # sign, with the gauze clear in the middle. Don’t cover the top of the gauze as you want the area to get some air.

The gauze will allow the area to weep and it will soak up the liquid and preventing it, for example, running down your leg, which is probably not the most pleasant sight. It will also help protect it from infection. It should also help stop you from itching the area. I would probably change the gauze every 12 hours or so, and keep putting gauze on until the area has stopped weeping. Remember to keep applying tiny amounts of hydrocortisone cream to the surrounding area to reduce itching.

Preventative care

I’m hoping that over time, my body will get used to the protein in the bites and will have a milder reaction. I never had to deal with mosquitoes when I was growing up in the UK, so my body hasn’t had a chance to get used to them until now.

The best thing you can do is to reduce the chances of getting bitten in the first place. I suggest the following:

  • Use anti-mosquito spray or insect repellent. Sprays containing DEET(N,N-Diethyl-meta-toluamide) are highly recommended, with concentrations of up for 50% if that’s possible.The concentration affects the length of time you will be protected, so you will need to reapply more often with lower concentrations. It can also have some effect on some materials, so read the label carefully. I prefer sprays, as they’re far easier to apply.
  • Keep as much skin covered as possible. It seems that mosquitoes are far more likely to bite  you on uncovered skin, so wear long sleeves and cover your legs. Remember to use insect repellent on any bare skin.
  • Use an insect repellent plug-in near your bed when you sleep.
  • Use a mosquito net if that’s practical.
  • Avoid areas with high concentrations of mosquitoes. They tend to prefer areas with stagnant water. This could be a natural pond or a man-made structure, like a container full of rain water.
  • You may want to take anti-histamines as a precautionary measure.

Remember that I am not a trained medical professional and you should seek medical advice rather than following something you read on the Internet.

Update: About a week or so after I posted this entry, the bites that I started getting didn’t have the same extreme reaction, so it looks like my body has gotten used to mosquito bites.

Have you had problems with severe allergic reactions to mosquito bites? How have you dealt with them? Let me know in the comments.

Image Credits: John Tann

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10 thoughts on “Dealing with extreme allergic reactions to mosquito bites

  1. I’m so glad there’s someone else that has had these reactions to mosquito bites! I’m exactly the same – had some horrendous bites the first couple of times I went to Thailand. They made my legs swell up – and yes, it’s always the ones below the knee that freak out, nowhere else. The nurses at the hospital I went to thought I’d been bitten by a snake 🙁

    Anyway, like you the allergic reaction has diminished over time and I haven’t had a bite freak out for a while, but I have to thank you for pinpointing *why* I had those reactions. No one has ever mentioned that it’s down to the protein the insects inject into you!

    1. Yes, I only have problems with bites below my knees. I currently live with a cat, so I’m wondering if it might not be fleas instead.

      My feet swelled up again over the weekend due to bites, but they didn’t blister anywhere nearly as badly as they did in the first two weeks of being in Rio; they just itch. I’m glad they’re less hassle now.

    2. I came home from Punta Cana a couple of days ago…my lower legs are a mess…swollen red & weeping bites…maybe they are in the sand ? No relief from topical creams. My Dr. actually put me on oral steroids for 3 days…I look contagious : /

  2. I have just returned from Thailand with horrendous mozzy bites . My ankles are swollen with big blisters from my bites . I have used incognito from Holland and Barrett which I can honestly say is brilliant because I got the bites when it had worn off . So I can say if I had used it correctly on the last day I wouldn’t of been bit because the whole 2 weeks I used it day and night even over my sun lotion and didn’t get bit .but unfortunately the last night it had worn off because I had forgot to take it with me so the results are bad . It’s the best spray ive ewe used I think any of the sprays work but you have got to spray before you go out also while your out you’ve got to keep it topped . People say sprays don’t work they Do if used correctly .

  3. I also get these bites and it’s good to hear that the reactions have diminished over time because I could be moving to Thailand and I’m terrified because a) I am a mosquito magnet b) I take reactions like those above c) Thailand has dengue fever, and I am probably about 100 times more likely to contract it than most other people who mosquitoes don’t seem to like as much!

  4. I just took your advice and popped my blisters! Hydrocortisone cream doesn’t work for me though–in fact, I’ve tried nearly everything to reduce the itching and have had very little success. My objective generally tends to be to get rid of the bite asap instead.

    About me and my bites: I should be in a laboratory. My entire life I have attracted mosquitos, spiders etc at an alarming rate. My latest bites are a result of an hour spent on a friends balcony in Manhattan–I landed 18 bites and the 5 others with me got a total of ZERO. I look like a leper because each bite (and all below the knees as well) is roughly an inch to 2 inches in diameter and half of them have developed blisters. I’ve noticed that my reaction vary by geography. NYC bites are the VERY worst (perhaps it’s the filth of the city that make the Mosquitos dirtier?). The mosquitos in the Caribbean, Hawaii, South America and Africa don’t give me reactions like this. Here, not only is my reaction worse, but I don’t learn of the bite for at least 12-15 hours after it occurred and my symptoms and the bite itself don’t leave for about 2 weeks. Elsewhere, I can feel the bite nearly right away (like a pinch) and it usually goes away in a day or 2. If anyone know why the mosquitos in NYC are so much worse, I’d love your thoughts. And any researchers out there, holler if you need a subject.

  5. My 1 year old got her first bite three months ago and to say the least it was horrific. Within 30 minutes she had a blister that popped and continued to drain all night. I take her in and they say she has a skin infection. This was just hours of being bitten. And now that this happened, it seems like she’s attracting mosquitos more and more. And the reactions are horrible especially if I don’t notice and she starts scratching. I use hydrocortisone for her, as well as Destin on the hives, and tonight we had to put some peroxide on it. I have it covered with gauze until she falls asleep to stop itching. I bought patchouli oil that I burn throughout the house. Most bug spray I don’t know if I can use, they all say 2 years and up. The doctor is negligent in my opinion (and yes we are switching), all she is content to do is prescribe my baby antibiotics and tell me to have her constantly on benedryl. If there’s any more ideas on prevention and treating please let me know! I am desperate.

    1. Hi I volunteer a lot in rural areas in Cambodia Laos Thailand and Malaysia, so I know the nasty bites can be from sand flies, mozzies and other critters. I strongly recommend tea tree oil, both useful for prevention and if unfortunately you have been bitten, just dab some on the bite. The other thing is to get lemongrass around the house. They are natural repellent. The local and me drink lemongrass daily until we exude the smell too. Non chemical way!

  6. I just happened to come across this post and thought it was very helpful. I’m from the UK and I first discovered I was sensitive to insect bites when I went on expedition to Brazil. Each bite turned my skin to mush and then turned into large 1-2inch blisters. They re-occurred when I temporarily lived in Beijing, and while doing some gardening on a hot summers day. I’d just learned to live with them. The tip on pre-empting the blisters by popping them as they form was very helpful. I had always tried to avoid popping them in fear of infection. But ultimately I would have to drain them when they became unbearably large. The post update gives me hope that someday my body will learn to adapt if exposed for long enough. Just wanted to give you shout out for sharing. There doesn’t seem to be much material about the condition online.

  7. OMG. Had mosuito bites jan 17, one blister jan 22 and just early this morning i got 9 blisters biggest is half an inch.. It got bigger after i went to the gym.. Now i am still hesistant to pop them. I am using Calmoseptine to cover them. I hope this will do good. By the way after hours of applying the ointment one blister looks like its liquid is coming out..

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