Answer:

Milk flowers contain many compounds that create their distinct scent. When the flowers bloom, these molecules diffuse into the air. In areas with many milk flower trees, a higher concentration of scent molecules makes the fragrance more intense.

When inhaled, these molecules not only affect the olfactory nerves (responsible for smell perception) but also stimulate the trigeminal nerve endings (cranial nerve V) in the nasal lining, which sense irritation. Stimulation of the trigeminal nerve triggers a reflex through the autonomic nervous system: blood vessels in the nasal lining dilate, leading to mucosal swelling and increased mucus secretion, causing nasal congestion, a runny nose, and sneezing. These symptoms are often temporary and subside upon leaving the scented area.

For individuals with an allergic predisposition, flower components like pollen can also trigger an IgE-mediated allergic reaction, leading to a runny nose and itchy eyes.

The strong scent of milk flowers can also be a trigger for migraines. The intense smell stimulates the trigeminal nerve, activating the neurovascular system in the head and face, releasing substances that cause vasodilation and neuroinflammation, leading to pain. Scent signals passing through brain regions associated with emotions can cause nausea, discomfort, and fatigue.

Doctor Phat is consulting a patient. Illustration: Tam Anh General Clinic District 7

Tolerance for milk flower scent varies among individuals, depending on olfactory and nasal mucosal sensitivity, allergic predisposition, history of migraines, asthma, or rhinitis, and environmental conditions.

Nasal congestion and headaches from smelling milk flowers are not sufficient grounds to conclude that you have allergic rhinitis. If a strong scent irritates sensitive nasal mucosa, causing an exaggerated reaction without an immune mechanism, it is typically non-allergic rhinitis.

If you only experience discomfort when exposed to strong odors (milk flowers, perfumes, smoke) and symptoms resolve immediately upon avoidance, it is likely irritant rhinitis. For an accurate diagnosis, you should consult a doctor for a nasal endoscopy and potentially specific tests to identify the cause.

Doctor Truong Tan Phat

Head of Otorhinolaryngology Department

Tam Anh General Clinic District 7