Hayfever: a medical herbalist’s view on seasonal allergies

Hayfever, or allergic rhinitis, is more than just a seasonal nuisance; it is an overreaction of the immune system. By understanding the pathophysiology of hayfever, from mast cell degranulation to histamine release, we can move beyond suppressing symptoms and start supporting the body’s natural balance through holistic herbal medicine.

How hayfever happens

The weather is starting to shift, and we are slowly entering a new season where nature awakes after many months of stillness. While some of us feel a renewed energy and the pull of outdoor life, others are filled with a sense of dread at the simple thought of taking a leisurely walk in the rolling hills of East Sussex.

This is all too familiar to me and my family. Late April and May, my husband and son begin to sneeze, deal with runny noses and swollen, red eyes, and feel generally exhausted and "bleh." It doesn’t help that we live on the edge of the South Downs, where crop fields and meadows of tall grasses abound.

This is hayfever, or seasonal allergic rhinitis. But how and why does it happen?

1. Priming phase (Sensitisation)

The first time the body encounters a specific pollen (from grass, trees or weeds), the immune system marks it as a threat. It produces IgE antibodies that act as a memory system. Your body is now "primed" and on high alert, waiting for the next encounter with that specific plant.

2. Mast cell response (Degranulation)

This is where the physical symptoms begin. These antibodies attach to the surface of Mast cells, specialised immune cells that act as your internal alarm system. When pollen binds to these antibodies, the mast cells degranulate, which essentially means they release their chemical contents into the surrounding tissue.

3. Release of histamine

The primary chemical released is histamine. Its job is to physically expel the allergen from the body. It causes the blood vessels to become more permeable (leading to swelling and a runny nose) and irritates nerve endings, which triggers the sneezing reflex.

Nettle leaf is very efficient in modulating inflammation and histamine release and is a staple herb in my hayfever formulas (more on that in a later post).

The "Atopic" family: is it in your DNA?

Have you ever wondered why some people are more prone to hayfever than others? In the clinical world, we use the term Atopy. This refers to a genetic predisposition to develop allergic diseases.

If there is a history of asthma, eczema, or hayfever in the family (often called the atopic triad), the immune system is essentially "pre-programmed" to be more sensitive to environmental triggers. When I look at my own family, I can see this genetic thread in action. However, while we cannot change our genetics, we can influence how those genes express themselves. This is where holistic support, focusing on the environment, gut health, and nervous system becomes so powerful.

Holistic view: beyond the nose

While conventional treatments often focus on blocking histamine receptors in the nose and eyes, holistic herbalism looks at why the system is so reactive in the first place. I like to look at three key areas that contribute to our allergic load.

1. The liver: our metabolic filter

The liver is responsible for breaking down and clearing excess histamine from the bloodstream. If the liver is "sluggish" or busy processing a heavy load of toxins, alcohol, or inflammatory foods, histamine can circulate for longer, making symptoms feel more intense and last much longer.

Hepatic herbs can help support the liver's ability to clear these allergic mediators and excess histamine, effectively lowering the body's total inflammatory burden.

2. Gut health and the "Barrier" connection

If you have met me or another herbalist, you will know how obsessed we are with the gut when it comes to restoring and maintaining good health. One of the main reasons is that around 70% of our immune system resides in the gut. This is why the health of our digestive tract is inseparable from our respiratory health.

• The microbiome: In a healthy state, these microbes act as a "tutor" to the immune system. However, when this ecosystem falls out of balance (a state known as dysbiosis) the immune system loses its training. Dysbiosis keeps the body in a state of chronic hyper-vigilance.

• Leaky gut (increased intestinal permeability): When the lining of the gut becomes inflamed, the "tight junctions" can begin to open. This allows undigested food particles and toxins to enter the bloodstream, keeping the immune system on "high alert."

• Mucous membrane integrity: The same type of tissue that lines your gut also lines your nose, throat, and lungs. By using “mucilaginous” (soothing and gloopy) or “vulnerary” (wound-healing) herbs to repair the gut lining, we can help strengthen the membranes in the nose and eyes.

  
  

3. Stress and the immune system seesaw: the Th1/Th2 imbalance

Imagine your immune system as a seesaw. On one side, you have Th1 responses, and on the other, you have Th2 responses. Allergic diseases are characterised by a broken seesaw that is heavily tipped toward the Th2 side, which drives your body to produce IgE.

Here is where stress comes in: when your brain perceives stress, it activates the HPA (Hypothalamus-Pituitary-Adrenal) axis. This alarm system tells your body to pump out heavy-duty stress hormones, including cortisol and adrenaline. These act like heavy weights on the seesaw, blocking the Th1 side and stimulating the Th2 side to produce even more allergy-driving proteins.

Chronic stress doesn't just make you "feel" worse; it biochemically locks your immune system into an allergic state. Here again, herbalists have access to a vast arsenal of adaptogenic herbs that have shown efficacy in modulating the HPA axis (another herbalist's obsession besides the gut!).

Conclusion

Hayfever is more than just a seasonal nuisance; it can be truly debilitating. I often see this most clearly during the spring and summer months when the hayfever season coincides with major exam periods. I have observed how exhausting (and frankly, unfair!) it can be for students to navigate their GCSEs and A-Levels while feeling physically unwell, dealing with "brain fog," and managing high levels of stress on top of their symptoms.

As we have explored, when we are under pressure, our internal "stress alarm" directly amplifies our allergic response. By looking beyond the nose and supporting the liver, the gut microbiome, and the nervous system, we can help lower the "allergic load." This systemic approach doesn't just aim to suppress a runny nose; it aims to build a more resilient foundation, allowing the body and the mind to function at its best, even when the pollen count is high.

COMING SOON: Check back regularly for my upcoming posts in the Materia Medica and Kitchen Herbalist sections. I’ll be sharing which specific plants can help with hayfever, the science of why they work, and practical steps you can take at home to prepare for the season ahead.

References:

• Akdis, C. A. (2021). Does the epithelial barrier hypothesis explain the increase in allergy, autoimmunity and other chronic conditions? Nature Reviews Immunology, 21(11), 739–751. https://doi.org/10.1038/s41577-021-00538-7

• Allergy UK. (n.d.). Hayfever (allergic rhinitis). https://www.allergyuk.org/about-allergy/types-of-allergies/hayfever/

• Dave, N. D., et al. (2011). Stress and allergic diseases. Immunology and Allergy Clinics of North America, 31(1), 55–68. https://doi.org/10.1016/j.iac.2010.09.009

• Niewiem, M., & Grzybowska-Chlebowczyk, U. (2022). Intestinal barrier permeability in allergic diseases. Nutrients, 14(9), 1893. https://doi.org/10.3390/nu14091893

• Pyun, B. Y. (2021). The atopic march: Progression from atopic dermatitis to allergic rhinitis and asthma. Pediatric Allergy and Immunology, 32(2), 279–284. https://doi.org/10.1111/pai.13409