The Hay Fever-Histamine Connection

HISTAMINE & HAY FEVER
The designation, “hay fever,” comes from an idea that seasonal allergy symptoms result from smelling hay. John Bostock, a medical doctor living in London in the 1800s, originally set out to figure out his own symptoms, as he dealt with occasional blocked sinuses and fatigue each June. He found others with the same symptoms and wrote an article about what he then called “summer catarrh” (Catarrh is a build up of mucus in the nose or throat). After his paper got passed around the medical establishment at the time, people got the idea that the symptoms came about from the smell of new hay in June — Hence, “hay fever.” Dr. Bostock didn’t agree –He thought it was some kind of recurring disease that was made worse by summer heat. For him, an escape to the cool seaside town of Ramsgate, in Kent, was helpful, and soon others also headed to the seaside to take in some fresh, sea air. Of course, the seaside also happened to be away from the high concentration of grass pollen, which is especially high in the month of June — at least in England. Histamine, as we know, is released by mast cells and then binds to one of four histamine receptors: H1, H2, H3, or H4. The histamine one (H1) receptor is the one that is activated with allergic rhinitis and produces symptoms like itchy, watery eyes, sneezing, and nasal congestion or a runny nose. It is also the one activated with hives and asthma. Benadryl, Zyrtec, Claritin, and Allegra are all H1 blockers, so they are often prescribed for allergies of this kind.TYPES OF HAY FEVER
There are two types of hay fever: seasonal allergies and perennial allergies. Seasonal allergies coincide with the pollination of certain plants and so occur seasonally, either spring or fall. Pollen from trees, grasses, and certain weeds are known to be the most common triggers. The springtime brings tree and grass pollination while fall is the time for ragweed pollination. Molds that are higher during these times of year and release spores into the air may also be to blame. Perennial allergies are those which last all year long. This type of allergic rhinitis is generally caused by indoor triggers such as dust mites, pet hair or dander, cockroaches, or mold. Some people may deal with both perennial and seasonal allergies and notice that their ongoing symptoms worsen in the spring and/or fall.WHAT CAN WE DO TO LESSEN EXPOSURE?
The American College of Allergy, Asthma, & Immunology (ACAAI) recommends the following for managing histamine levels and symptoms:- Monitor pollen and mold counts via newspaper, radio, or television reports and keep windows and doors shut during peak times. Mid-morning and early evening are high points during the day.
- Wear glasses or sunglasses when you’re outside to avoid eye exposure to pollen.
- Get a pollen mask (NIOSH-rated 95 filter) and wear when doing outdoor activities like mowing the lawn, raking, or gardening.
- Don’t hang clothing, towels, or sheets outside to dry as the pollen may cling to the fabric and be brought inside.
- Take a shower and put on fresh clothes after spending time outside.
- Keep your home free of dust and dust mites and wash your bedding frequently.