The common term “cedar” applies to a variety of coniferous trees in the cedar, juniper and cypress families. All types produce allergenic cedar pollen, which causes allergic rhinitis, or hay fever, in some people whose bodies are abnormally sensitive to this usually benign substance. True cedars include the atlas cedar and cedar of Lebanon. Pseudo-cedars that are native to the United States include the Western red cedar and mountain cedar. During winter or early spring when their pollen becomes airborne, allergy patients experience respiratory and other symptoms.
Eye Symptoms
The body’s release of histamine in response to ingesting cedar pollen allergens creates inflammation, itching and fluid migration into the mucous membranes, according to the Cleveland Clinic. This is why the onset of allergic rhinitis results in swollen eyelids and red, itchy, watery eyes. Dark circles beneath the eyes, called allergic shiners, are signs of inflammation in the local sinus area. These shiners may persist beyond the cedar’s reproductive period in patients with multiple seasonal or perennial allergies.
Nose Symptoms
The histamine release that accompanies hay fever allergy to cedar makes the mucous membranes of the nose itch, according to the Mayo Clinic. Inflamed nasal sinuses may cause congestion, which may alternate with a runny nose associated with heavier than normal mucus production. This interference with patients’ sense of smell may cause a reduced sense of taste as well.
This thickened mucus is designed to block any more pollen from entering the nasal passages. The sneezing reflex, triggered by histamine levels, drives out pollen granules along with mucus. As allergic rhinitis progresses, the excess mucus drains from the nasal passages, and postnasal drip develops.
Throat Symptoms
Mucus from postnasal drip trickles into the throat, to be swallowed and eliminated through the digestive tract. Hay fever-induced histamines also inflame the throat membranes, making them itch. The symptomatic response may be a cough and sore throat during cedar pollen season, as the University of Maryland (UM) Medical Center reports.
Other Symptoms
Allergic rhinitis conditions from some cedar pollen allergies, such as to mountain cedar in the Southwest United States, can be debilitating. Difficulty sleeping for extended periods due to sneezing and other breathing symptoms can lead to fatigue, headache and poor concentration. The UM Medical Center adds facial tenderness and pain to this list, as evidence of ongoing sinus pressure. If patients notice an absence of hay fever symptoms in the presence of cedar trees, these may be females of the species. The National Institutes of Health note that only the male cultivar of trees such as the mountain cedar produce allergens.
