Allergies and loss of smell

Allergic rhinitis usually brings sneezing, itching, clear nasal discharge, and congestion, with smell changing as the blockage varies. A cold can also reduce smell through inflammation and mucus. COVID-19 can present with a sudden loss or alteration of smell, sometimes without marked nasal blockage, and smell disturbance may persist as part of Long COVID. Ongoing congestion, facial pressure, thick discharge, or repeated flare-ups can occur with chronic sinusitis. The timing and accompanying nasal symptoms help a clinician separate these possibilities.

Reduce exposure to known allergens and use any prescribed nasal treatment consistently with the correct technique. Saline rinsing may clear mucus, but prepare it with sterile, distilled, or previously boiled and cooled water and keep the device clean. Do not place essential oils or irritating substances inside the nose. Because smell loss can hide smoke, gas, or spoiled food, check that alarms work, follow food storage dates, and ask someone with a normal sense of smell to check anything uncertain.

Seek urgent care if smell loss follows a significant head injury or occurs with facial weakness, trouble speaking, weakness in an arm or leg, confusion, or a sudden severe headache. Arrange a clinical review when the loss is sudden without congestion, affects only one nostril, persists after other nasal symptoms settle, or comes with recurrent nosebleeds, severe facial pain, or a nasal growth. Follow current local advice on respiratory infection testing and precautions if a new infection is possible.

Tell the clinician whether smell is reduced, absent, or distorted and whether taste seems different because flavours are harder to detect. Ask if the nasal passages need examination, whether your allergy treatment should be adjusted, and whether smell training is suitable after the cause is considered. Mention recent infections, head injury, sinus problems, nasal surgery, smoking, chemical exposure, and new medicines. A diary of congestion and trigger exposure can reveal whether the change follows an allergic cycle.