How Histamine Impacts Your Asthma

Histamine is a natural chemical produced by the body. It has many functions, including acting as a relay messenger between different parts of the immune system. Overactivity of histamine is associated with allergies.

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How Histamine Works

Histamine mediates your body's natural defense mechanisms to protect you from harmful substances. Asthma and allergy symptoms can develop when your body over-reacts to something that is not particularly harmful but that has caused your immune system to react.

Immune cells called mast cells and white blood cells known as basophils release histamine when you are exposed to allergens. When histamine is released, the allergic response begins.

This reaction can affect different areas of your body, causing a range of symptoms:

  • Your eyes may become itchy and watery
  • Your throat may be sore and scratchy
  • Wheezing, chest tightness, shortness of breath, or a cough

If you have asthma, histamine may promote bronchoconstriction—tightening of the muscles surrounding the airways in your lungs—and production of mucus.

Medications That Block Histamine

Antihistamine drugs are used in the treatment of the allergic symptoms caused by the release of histamine. Some popular anti-histamine medications include Zyrtec (cetirizine), Allegra (fexofenadine), Claritin (loratadine), and Benadryl (diphenhydramine).

Leukotriene modifying drugs, such as Singulair (montelukast), may also help by reducing the allergic response. The FDA has approved this type of drug for treating refractory allergic rhinitis and asthma. Refractory conditions are those that do not improve with standard therapy—this treatment is not recommended for use as a first-line treatment for allergic rhinitis or asthma.

A black box warning was recently added due to severe neuropsychiatric side effects in a subset of patients using Singulair, and if you have a history of mental illness, your doctor might recommend that you avoid this treatment option.

It should also be noted that while histamine can lead to bronchoconstriction, antihistamines are not a first-line agent to treat an asthma attack. Rescue inhalers like albuterol are typically prescribed for patients to carry and use when acute asthma symptoms begin.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Panula P. Histamine, histamine H3 receptor, and alcohol use disorder. Br J Pharmacol. 2020;177(3):634-641. DOI:10.1111/bph.14634

  2. Yamauchi K, Ogasawara M. The role of histamine in the pathophysiology of asthma and the clinical efficacy of antihistamines in asthma therapy. Int J Mol Sci. 2019;20(7) doi:10.3390/ijms20071733

  3. FDA. Singulair (Montelukast) and all montelukast generics: strengthened boxed warning - due to restricting use for allergic rhinitis. Published online September 9, 2020.

  4. FDA. FDA requires Boxed Warning about serious mental health side effects for asthma and allergy drug montelukast (Singulair); advises restricting use for allergic rhinitis. Published online March 13, 2020.

By Pat Bass, MD
Dr. Bass is a board-certified internist, pediatrician, and a Fellow of the American Academy of Pediatrics and the American College of Physicians.