Seasonal Allergies: What You Need to Know (What is Histamine?)

Spring brings beauty—wildflowers, sunshine, gentle breezes, renewed energy—but also a common downside: pollen. Our dry spring has led to many patients experiencing more severe and prolonged seasonal allergies this year. The Centers for Disease Control and Prevention estimates that allergies are the 6th leading cause of chronic illness in the U.S., with an annual cost in excess of $18 billion. You are not alone.

What Is Histamine? During an allergic reaction, histamine—a chemical messenger and neurotransmitter—gets released from mast cells (a type of white blood cell) in response to foreign proteins in the blood, such as pollen. This triggers well-known symptoms: itchy, watery eyes, sneezing, congestion, and swelling.

Outside allergy season, histamine regulates appetite, stomach acid, hormones, arousal, reproduction, cognition, and immune function. Allergies result from an excessive immune response and histamine release to ordinarily harmless substances. To manage allergy symptoms, many people turn to antihistamines, which work by blocking histamine receptors and reducing the effects of histamine.

The Problem with Antihistamines: For the over 50 million Americans who suffer from seasonal allergies, antihistamines are often the first line of defense. Common side effects from routine use include drowsiness, dizziness, headache, dry mouth, and blurred vision. These medications can also interact with antidepressants, indigestion medications, and some cough and cold remedies.

While it is hard to argue that these pharmaceuticals can be helpful in the short term, daily use of antihistamines may have unintended consequences. The body may produce more histamine due to blocked receptors, which can worsen symptoms. These drugs can also deplete enzymes that break down histamine (DAO, HNMT), making it difficult for the body to metabolize histamine, which can cause symptoms such as digestive issues, hives and eczema, anxiety, flushing, menstrual changes, rhinitis, headaches, and malaise.

A 2016 study published in JAMA Neurology found an association between individuals taking anticholinergic medications long-term, such as Benadryl (diphenhydramine), and exhibiting signs of reduced brain size and activity, as well as poorer performance on memory and cognitive tests.

In March 2025, a study published in the journal Gut found that loratadine (Claritin), along with several other antihistamines, inhibited more than 10 beneficial microbial strains, suggesting a potential impact on gut health.

An Alternative: Chinese Medicine (CM) addresses allergies by addressing the underlying causes and imbalances within the body, while also treating the symptoms. This approach aims to strengthen the body’s ability to heal itself and prevent future allergic reactions. CM considers a patient’s inherited constitution and lived experience, including factors such as diet, physical activity, stress, environmental factors (pollution and smoke), overwork, excessive exercise, and overeating, and then designs a treatment plan that incorporates acupuncture and herbal medicine.

Herbal medicine plays a crucial role in rebalancing the body’s systems. Recent research has shown bi-directional immune-modulating properties, meaning that the synergistic effect of the herbs in the formula can balance the immune system, affecting both hypo- and hyperactive immune responses. Acupuncture is an effective treatment for allergies due to its immune-modulating, anti-inflammatory, and analgesic properties.

Adverse side effects related to the use of Chinese medicine are rare and typically mild and short-lived if they occur at all. Thanks to centuries of evidence, we can confidently state that the benefits outweigh the risks.

Dr. Jennifer Savage is a Doctor of Acupuncture and Chinese Medicine and the owner of Wú Wéi Wellness in Old Town Beaverton, with over 25 years of experience in healthcare. To schedule an appointment, call 503.530.8097 or visit www.bewuweiwell.com.