Histamine Intolerance, Mast Cells, and COVID-19

I don’t need to introduce you to COVID-19. We’ve been living in a state of uncertainty since March during this pandemic. There is not a minute passing that you are not reminded of this virus. Perhaps you know people who have been infected or you have gotten sick yourself. 

If you have histamine intolerance or mast cell activation syndrome (MCAS), you may be wondering if this increases your risk factor for COVID-19 symptoms and complications. While this is a novel virus and we don’t have enough knowledge or evidence, there has been some new scientific discussion on the role of histamine intolerance and mast cells in COVID-19. An increasing number of functional and natural medicine doctors are suggesting a low-histamine diet. Today, I want to bring you the latest scientific information and discuss what we know.

In this article, you will learn about the potential connection between histamine intolerance, mast cells, and COVID-19. I will discuss what current evidence suggests regarding histamine and COVID-19. I will offer some tips on how to support your body if you have histamine intolerance and mast cell activation syndrome. 

Histamine Intolerance, Mast Cells, and COVID-19

COVID-19 is a virus. Just like with any other viral infection, it is very important to look at your immune system’s health when it comes to both prevention and recovery. 

If you are dealing with histamine intolerance, there are a number of things that it’s important to look at when it comes to COVID-19. You need to understand the branches of your immune system. You also need to understand your current immune health and immune responses in relation to histamine intolerance and mast cell activation syndrome (MCAS). You need to be aware that both histamine intolerance and COVID-19 may release inflammatory cytokines that may worsen your symptoms. We also need to touch on whether or not COVID-19 can worsen or lead to histamine intolerance symptoms.

Branches of Your Immune System

Your immune system has two branches: Th1 is the immune system that you are born with and Th2 is the adaptive immune system you acquire throughout your life from exposure to foreign invaders from your environment. They are both very important. Your adaptive immune system plays an important role in infectious diseases. If you’ve already had chickenpox, your adaptive immune system has built up mechanisms to protect you from it in the future. While life-long immunity may not happen in all cases, exposure to viruses and bacterial infections helps to build up your adaptive immune system and create resistance to help to prevent future infections or aid recovery in the future.

Histamine and Your Immune System

Histamine gets a bad rap because we usually hear about them in the context of anti-histamine creams and medication. But histamine is actually essential for your health and plays an important role in your immune system. Your cells, including your T-cells, have histamine receptors and are able to release histamine. This is key when it comes to COVID-19 and may help us to understand how serious symptoms can develop (1).

COVID-19 is a new coronavirus and its behavior and effects, including its effects on your T-cells and another key immune mechanism, are still being investigated. However, we can also gain some insights from research done on two similar coronaviruses, SARS and MERS, both of which have caused a serious outbreak in the past decades. From what we understand, the severity of your infection depends on how much the virus is able to suppress the immune and T-cell response.

You are probably aware that COVID-19, in most cases, is far more dangerous for older people and those with a compromised immune system. It is also riskier for adults than teenagers and children. While children are able to carry the virus, in most cases, they only develop mild symptoms or no symptoms at all. 

Researchers suspect that this happens because children have a higher T-cell immune response. Their bodies are still learning and adapting to their environments. While they may pick up the virus, their bodies seem to be able to contain it better than adult bodies. Adult bodies have more inactive T-cells due to aging hence their immune systems are unable to respond as quickly and as well leaving a greater risk of symptoms (2, 3).

When the activation of either branch of your immune system is delayed, the environment within your body may also become more favorable for replication. Viral replication can also lead to hyperinflammatory conditions, which can increase the severity of the disease. In some cases, these hyperinflammatory conditions may also be connected to increased histamine release or histamine intolerance (4, 5).

Furthermore, histamine intolerance and MCAS can also seriously affect your immune system and inflammatory responses. If you have histamine intolerance or MCAS, especially when left untreated, your immune system is already highly active and alert characterized by an array of active mast cells.

You mast cells are a major source of histamine in your body. When triggered they release histamine, which in large amounts that can lead to too much histamine and related symptoms in your body. When triggered, mast cells can also release other chemicals along with histamine. One of these chemicals is cytokines, which is very important to talk about when it comes to COVID-19 (6).

Cytokines, Histamine Intolerance, Mast Cells, and COVID19

Histamines are inflammatory regulators. This is important and beneficial when it comes to an allergic reaction, however, it can become a problem in the case of histamine intolerance and COVID-19. Histamine intolerance means that you have too much histamine in your body, which can lead to a long list of symptoms and health issues. Beyond histamine intolerance, mast cell activation syndrome (MCAS) can also lead to increased histamines and related symptoms. 

Your mast cells are white blood cells found in tissues throughout your body and sometimes in your blood as well due to certain infections and diseases that they may attempt to repair once the health danger is gone. Your mast cells play an important role in your immune system as they store inflammatory mediators, including histamine inside granules. When you experience an allergic reaction or other triggers, such as mold, viruses, chemicals, heavy metals, or toxins, your mast cells will cause a response that will trigger the release of histamine and other chemicals. This can become a serious health problem when this happens often and your body is unable to take care of the excess histamine. 

When histamine pathways are stimulated, it can increase inflammatory reactions and the release of cytokines. Cytokines are signaling proteins that act as humoral regulators that regulate a variety of processes in your body and play an important role in your immune response. However, releasing too many cytokines can result in a serious problem. A cytokine storm is a strong immune reaction characterized by too many cytokines being released into the blood. Moreover, this histamine and cytokine release happens in areas of your body where histamines are most commonly found – one of these areas is tissues in your lungs, which may also be affected by COVID-19 (7, 8, 9).

Furthermore, current information suggests that COVID-19 can also trigger cytokine release. In fact, you might’ve heard of the cytokine storm in relation to more serious COVID-19 cases. Cytokine release seems to be one of the biggest issues that can lead to lung tissue damage in COVID-19. 

If your body is already releasing cytokines because of histamine intolerance or MCAS and now releasing them because of a COVID-19 infection as well, it can possibly amplify your symptoms. Histamine intolerance or MCAS may also result in respiratory or lung-related symptoms, including asthma, serious allergies, and chronic respiratory symptoms, which may put you at a higher risk of more serious COVID-19 symptoms. 

While there is no clear research or information saying that histamine intolerance or MCAS will put you in a higher risk category, one scientific article published in the Journal of Allergy and Clinical Immunology has discussed the risk and management of patients with MCAS and mastocytosis during the COVID-19 pandemic. Their recommendations included increased preventative measures, video visits with doctors, and avoiding immunosuppressants. While we need more research and evidence, there seems to be a valid concern for those with histamine intolerance and MCAS because both increase cytokine release and possible breathing-related and respiratory symptoms (10).

Antihistamine and the Cytokine Storm

New research studies also support the notion that histamines may play a role in the development of a cytokine storm in COVID-19 and exploring anti-histamines as part of the treatment protocol. One article by a group of scientists published in Travel Medicine and Infectious Diseases has discussed that the histamine, as the main mediator released by the immune system, may initiate an abnormal immune response that may result in a cytokine storm or even multi-organ failure. They suggested that the use of anti-histamine medication should be explored to potentially aid the treatment of cytokine storms in COVID-19 (11).

An article published in The Centre for Evidence-Based Medicine discussed the potential use of leukotriene antagonists (used for severe asthma), anti-histamine, and mast cell stabilizers in COVID-19. There is also a clinical trial currently on its way to look at the histamine antagonist, Fomatidine as a potential option for COVID-19. Again, we don’t have enough evidence yet, but the potential that these leukotriene antagonists, anti-histamines, and mast cell stabilizers may benefit some COVID-19 patients, further support the role of histamines in COVID-19. I suspect that there will be a lot more research coming out on this in the future (12, 13, 14).

Long-Term Implications

When thinking about COVID-19, it is not enough to discuss the course of the illness, we must touch upon potential long-term consequences. Many recovered patients of COVID-19 are dealing with long-term effects of the infections. Many patients seek help for chronic fatigue and other chronic symptoms, including migraines, sinusitis, or shortness of breaths months after being ill. While we don’t have evidence that this is because of histamine, Dr. Tina Peers, a doctor who treats women with histamine intolerance and MCAS has recently explained in a BBC report that elevated histamine levels from the infection may lead to these on-going symptoms post-COVID-19 recovery (15)

Again, at this point, we don’t know whether COVID-19 can lead to histamine intolerance and related symptoms in the long-run. However, considering the nature of some of the long-term symptoms, this should be investigated. I believe that we will learn more about this as research on the long-term implication of COVID-19 unfolds and we gain a better understanding of the disease.

What You Can Do

When it comes to COVID-19, prevention is very important. Wash your hands regularly and maintain proper hygiene. Follow current guidelines. If you suspect COVID-19 infection, get tested. If you have COVID-19, make sure to tell your doctor if you have histamine intolerance, MCAS, or any other inflammatory, chronic, or other health conditions so they can take it under consideration during your treatment.

If you have histamine intolerance or MCAS, it is important that you follow a low-histamine nutrition plan and support your body with a healthy lifestyle. Disclaimer: It is important that I mention that none of these tips are proven to prevent or cure COVID-19 or related health issues. My recommendations are simply designed to support your health and wellness if you have histamine intolerance or MCAS. That being said, here is what I recommend for histamine intolerance and MCAS:

Support Your Immune System

Support your immune system and reduce inflammation through a healthy diet, lifestyle and supportive supplements like Ultimate Immune Support and HistoRelief to support mast cells and histamine levels in the body. Eat a nutrient-dense, anti-inflammatory, low-histamine whole food diet rich in greens, vegetables, fruits, healthy fats, and clean protein. Exercise regularly and spend plenty of time in nature. Drink plenty of water. Sleep at least 7 to 9 hours every night. Reduce stress. And don’t forget to laugh.

Try The 4-Phase Histamine Reset Plan

If you have histamine intolerance or MCAS, I recommend that you follow a low-histamine diet high in nutrients from whole foods, including greens, vegetables, fruits, healthy fats, and clear protein. Remove all histamine foods for one to three months. After the initial elimination phase, slowly re-introduce them one by one following The 4-Phase Histamine Reset Plan while tracking your body’s reactions. 

To understand each step of this simple yet refined system, I recommend that you read my book, The 4-Phase Histamine Reset Plan: Getting to the Root of Migraines, Eczema, Vertigo, Allergies and More where I explain everything about histamine intolerance and MCAS and each phase of the plan in detail and offer my favorite low-histamine recipes to nourish your body. For further tips and the latest information on a low-histamine lifestyle and delicious low-histamine recipes, follow my blog and social media. You are not alone. I am here to support you along the way.

Final Thoughts

COVID-19 is a novel coronavirus. We don’t fully understand how it works and at this point, there is no cure. New studies and scientific discussions are coming out daily to help us gain a better understanding of the disease. There has been some new scientific discussion on the role of histamine intolerance and mast cells in COVID-19. At this point, we don’t know what role a low-histamine diet may play in this disease and more research is needed on this topic. However, supporting your health is important regardless of this current pandemic. If you are dealing with histamine intolerance or MCAS, it is absolutely critical that you take steps and support your body with a low-histamine diet and healthy lifestyle strategies.

If you are dealing with symptoms of histamine intolerance or mast cell activation syndrome, I invite you to schedule a consultation with us. I can help to identify the root cause of your problems and recommend a personalized treatment plan to repair your body and regain your health and well-being. Schedule your consultation here.

1. Ferstl, R., et al. Histamine regulation of innate and adaptive immunity. Front Biosci (Landmark Ed). 2012 Jan 1;17:40-53. Link Here
2. Liu, W., et al. Detection of Covid-19 in Children in Early January 2020 in Wuhan, China. The New England Journal of Medicine. 2020. Link Here
3. Zhao, J., et al. T Cell Responses Are Required for Protection from Clinical Disease and for Virus Clearance in Severe Acute Respiratory Syndrome Coronavirus-Infected Mice. Journal of Virology. 2010. 8(4): 9318–9325 Link Here
4. Prompetchara, E., et al. Immune responses in COVID-19 and potential vaccines: Lessons learned from SARS and MERS epidemic. Asian Pac J Allergy Immunol DOI 10.12932/AP-200220-0772 Link Here
5. Prompetchara, E., et al. Immune responses in COVID-19 and potential vaccines: Lessons learned from SARS and MERS epidemic. Asian Pac J Allergy Immunol DOI 10.12932/AP-200220-0772 Link Here
6. Branco, A., et al. Role of Histamine in Modulating the Immune Response and Inflammation. Interplay between Hormones, the Immune System, and Metabolic Disorders. 2018. 9524075 Link Here
7. Dunford, P., et al. The histamine H4 receptor mediates allergic airway inflammation by regulating the activation of CD4+ T cells The Journal of Immunology, vol. 176, no. 11, pp. 7062–7070, 2006. Link Here
8. Thangam, E., et al. The Role of Histamine and Histamine Receptors in Mast Cell-Mediated Allergy and Inflammation: The Hunt for New Therapeutic Targets. Front. Immunol., 13 August 2018. Link Here
9. Kritas, S. K., Ronconi, G., Caraffa, A., Gallenga, C. E., Ross, R., & Conti, P. (2020). Mast cells contribute to coronavirus-induced inflammation: new anti-inflammatory strategy. Journal of biological regulators and homeostatic agents, 34(1), 10.23812/20-Editorial-Kritas. Link Here
10. Valent P. Risk and management of patients with mastocytosis and MCAS in the SARS-CoV-2 (COVID-19) pandemic: Expert opinions. Journal of Allergy and Clinical Immunology. Volume 146, Issue 2, August 2020, Pages 300-306. Link Here
11. Eldanasory OA, Eljaaly K, Memish ZA, Al-Tawfiq JA. Histamine release theory and roles of antihistamine in the treatment of cytokines storm of COVID-19. Travel Med Infect Dis. 2020 Sep-Oct;37:101874. doi: 10.1016/j.tmaid.2020.101874. Epub 2020 Sep 3. PMID: 32891724; PMCID: PMC7470786. Link Here
12. Raymond M. Mast cell stabilizers, leukotriene antagonists and antihistamines: a Rapid review of effectiveness in COVID-19. The Centre for Evidence-Based Medicine. Link Here 
13. Lowe D. Famotidine, Histamine, and the Coronavirus. Link here
14. Mutisite Adaptive Trials fo COVID-19. Clinical Trials. Link Here
15. Haseler N. Long Covid: ‘I don’t have a life, I currently have an existence’. BBC. Link Here








Hi, I am Dr. Becky Campbell. I work with men and women who’ve had a health set back and are willing to do whatever it takes to reach optimal health so they can perform their best in their careers and be fully present with their family again.

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