It’s a balmy summer evening. The stars are twinkling in the sky and you hear the faint chirping of the insects outside. Everything is perfect and you’re feeling calm and relaxed.
Suddenly, your bubble of serenity bursts. Something has bitten your ankle. You’re alerted right to the spot, because it immediately begins to itch; as it does for most people. But for you, it doesn’t stop there.
The itching becomes unbearable. Your immune system has sent in its troops thinking this single mosquito bite poses a significant threat to your body. And it begins the fight against it.
And, before you know it, you have a quarter-sized welt that you know is going to itch and be uncomfortable for days.
It’s a sure sign you are experiencing an overactive histamine response to bug bites. But, what exactly is this condition? And why does it happen to some people and not others?
The Normal Reaction to Bug Bites
Let's start by looking at someone who doesn't have histamine intolerance.
When a mosquito lands on someone and decides they're going to be their next tasty meal, it pierces their skin with its proboscis in order to be able to suck up the blood. As it feeds, it injects saliva. But, it’s not just any saliva!
Because there’s damage to the body - after all, the proboscis has pierced the skin and blood vessel - blood will start to clot in that area to prevent blood loss. The mosquito’s saliva contains special enzymes that help to keep the viscosity of the blood fluid enough to continue to consume. A clot would makes it impossible to do, so these special enzymes in the saliva help to facilitate the ability to keep drawing the blood.
But, it’s these enzymes that cause the problem (1).
The same thing happens when you’re bitten by another type of bug, from fire ants to fleas and bedbugs. They all leave you with a similar toxic parting gift.
This is what the body reacts to, and the reason there's itching and swelling at the site.
Basically, the immune system picks these toxins up in the blood and activates the mast cells—a type of cell that's an integral part of the immune system. The mast cells then release histamine, signaling the immune system to take action (2).
Blood flow to the area increases to facilitate the delivery of white blood cells to the spot so they can begin the attack (3). With histamine and increased blood flow to the area, there’s little wonder why the site swells and itches.
Now, in those who are not intolerant to histamine, once the allergen has been neutralized by the immune system, histamine is degraded and the allergic reaction ends. The bite might itch for a short while, but remains in a state of only a mild irritation with minor swelling in the area (4).
What is an Overactive Histamine Response?
If you're sensitive to histamine, it's a different story! And while nobody likes being bitten by bugs, if your body overreacts to the substances insects inject into your skin, it’s likely you dread them more than most.
An overactive histamine response to bug bites means your body’s reaction is a bit over the top, leading to more intense symptoms. So, instead of a small raised, itchy bump, you end up with a golf-ball sized wheal and fierce itching for days.
These exaggerated symptoms can include:
- Intense itching that persists for days or even weeks
- Large, swollen areas around the bite site
- Widespread redness and warmth
- In severe cases, more widespread systemic reactions like hives and difficulty breathing.
Several factors contribute to overactive histamine responses. You might have a genetic predisposition to being more sensitive to them, have too much histamine flowing around your body to begin with, or be allergic to insect bites where your immune system simply raises the alarm more readily when you're stung. Underlying health conditions and environmental factors also play a role.
While any insect bite can potentially cause an overactive response, some of the more common offenders we see causing these more severe histamine overreactions include mosquitos, bed bugs, fleas, fire ants, and certain types of flies (5).
The Link Between Overactive Histamine Response and Histamine Intolerance
An overactive histamine response can be closely related to histamine intolerance—a condition characterized by elevated histamine levels. Since your immune system continues to protect you from potential harm and you eat foods that might be high in histamine, levels build up in your body (6).
In addition to more histamine being produced, people with histamine intolerance often have trouble breaking down histamine due to low levels of DAO.
For a while, there might not be any obvious signs this is happening. The trouble comes when there's no break in the histamine response.
Imagine a bucket slowly filling up with water. All the water is contained but, should the bucket continue to fill, water will begin to spill over the top, making a mess.
Now think about your histamine levels as the water and your body as the bucket.
Histamine levels rise slowly, without causing any unusual symptoms. However, once the body reaches its tolerance to histamine, it starts “overflowing”. Histamine leaves as big a mess as the water would leave on the floor. The mess in this case is expressed by the body as bothersome - sometimes debilitating - symptoms.
When your “histamine bucket” is full, almost anything can trigger an intense allergic response as it causes your histamine levels to rise further, like a bug bite would do. It’s this histamine overload that leaves people who are living with histamine sensitivity to experience an over-the-top histamine reaction to insect bites and stings.
Diagnosis and Treatment
If you experience an overactive histamine response to bug bites, you may want to consult with a healthcare professional. They might do allergy tests and recommend keeping a symptom diary to identify any patterns, especially if the bites or stings get worse with each event.
Treatment options can include:
- Over-the-counter antihistamines that help to reduce itching and swelling
- Topical corticosteroids for severe localized reactions
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In some cases, prescription medications may be necessary, or you’ll be prescribed an Epi Pen should you be at risk of a life-threatening anaphylactic reaction should you be bitten again
There are additional, everyday strategies you can employ in your life that may be beneficial if you have histamine intolerance and an overreaction to bug bites as a result:
- Follow a low-histamine diet that focuses on fresh whole foods while eliminating those high in histamine (7).
- Take supplements that can support the way your body breaks down histamine, such as diamine oxidase (DAO), or those that help reduce histamine levels, like natural antihistamines.
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Avoid known histamine triggers common in the environment like dust and pollen. Be sure to dust your home regularly and use an air purifier should this be possible.
Prevention: Your First Line of Defense
While you can’t change your body’s inherent response to bug bites, you can take steps to minimize your exposure and the overall reaction.
First, consider using effective insect repellents to keep bugs at bay. Look for those containing low histamine and non-toxic ingredients.
Also, wear protective clothing, especially during peak bug activity times, which are typically at sunup and sundown.
Finally, take charge of your living environment—cover your bed with a mosquito net, use insect-repellent bedding, and treat your yard for pests if necessary.
When to Seek Immediate Medical Help
In most cases, an overactive histamine response to bug bites can be uncomfortable, but it should not be inherently dangerous or life-threatening.
Signs that you need to get help immediately, and a sign of a severe allergic reaction, include:
- Difficulty breathing
- Swelling of the face, tongue, lips, and/or throat
- Dizziness or fainting
- Nausea and vomiting
These symptoms could indicate an anaphylactic response, a life-threatening condition that requires immediate medical attention.
Living with Overactive Histamine Response: Knowledge is Power
Managing an overactive histamine response to bug bites is about being proactive. In addition to taking the steps to reducing your body’s histamine load, stay aware of your environment, keep antihistamines on hand, and reach out to your healthcare provider if your symptoms are unusually severe and persistent.
If you’re dealing with overactive responses and histamine intolerance, a holistic approach that includes dietary management, stress reduction, and careful monitoring of your symptoms can improve your quality of life.
References:
- About Mosquito Bites | Mosquitoes | CDC. Mosquitoes. Available from: https://www.cdc.gov/mosquitoes/about/about-mosquito-bites.html
- Fong M. Histology, Mast Cells - StatPearls - NCBI Bookshelf. National Center for Biotechnology Information. Available from: https://www.ncbi.nlm.nih.gov/books/NBK499904/
- The Biogenic Amines - Neuroscience - NCBI Bookshelf. National Center for Biotechnology Information. Available from: https://www.ncbi.nlm.nih.gov/books/NBK11035/
- Vander Does A, Labib A, Yosipovitch G. Update on mosquito bite reaction: Itch and hypersensitivity, pathophysiology, prevention, and treatment. Frontiers in Immunology. 2022 Sep 21; Available from: http://dx.doi.org/10.3389/fimmu.2022.1024559
- Singh S, Mann B. Insect bite reactions. Indian Journal of Dermatology, Venereology, and Leprology. 2013;(2):151. Available from: http://dx.doi.org/10.4103/0378-6323.107629
- Comas-Basté O, Sánchez-Pérez S, Veciana-Nogués MT, Latorre-Moratalla M, Vidal-Carou MDC. Histamine Intolerance: The Current State of the Art. Biomolecules. 2020 Aug 14;10(8):1181. doi: 10.3390/biom10081181. PMID: 32824107; PMCID: PMC7463562.
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Sánchez-Pérez S, Comas-Basté O, Veciana-Nogués MT, Latorre-Moratalla ML, Vidal-Carou MC. Low-Histamine Diets: Is the Exclusion of Foods Justified by Their Histamine Content? Nutrients. 2021 Apr 21;13(5):1395. doi: 10.3390/nu13051395. PMID: 33919293; PMCID: PMC8143338.
Anita Tee
My name is Anita Tee. I'm a nutritional scientist specializing in histamine intolerance. I hold a Master of Science in Personalized Nutrition and a Bachelor of Science in Human Biology and Psychology.
For the past ten years, I have used my experience in nutritional and medical health sciences to create a scientifically backed, natural approach to healthcare that relies 100% on evidence-based research.
As I previously suffered from - and overcame - histamine intolerance, my focus is to increase recognition and expand the available resources and protocols for resolving the disorder. To date, I have helped over 4,000 individuals fully resolve or better manage their histamine intolerance symptoms.
