Allergies and a runny nose: what to know

Symptoms may come and go with dust, pets, pollen, mould or another exposure. Fever, marked body aches or feeling generally unwell point away from a simple nasal allergy and deserve a broader assessment.

In allergic rhinitis, the immune system reacts to a normally harmless airborne substance. The nasal lining becomes inflamed and releases fluid, producing dripping, congestion and repeated sneezing. Itching of the nose, throat or eyes makes an allergic cause more recognisable.

A cold can also present with a runny nose, but it is more likely to include a sore throat and may later produce thicker mucus. Mucus colour alone cannot reliably identify a bacterial infection. Symptoms that follow a consistent place, season, animal or cleaning activity can help reveal an allergy trigger.

Notice when symptoms start and reduce the relevant exposure where practical. Rinse the nose with sterile saline, shower after heavy outdoor exposure, wash bedding regularly and keep pets out of the bedroom if animal contact is a trigger. Avoid cigarette smoke and strong fragrances, which can further irritate the nasal lining.

A pharmacist or clinician can help select an antihistamine or a corticosteroid nasal spray and explain correct use. Aim a nasal spray slightly outwards, away from the centre wall of the nose. Check suitability before treatment if you are pregnant, have another medical condition, take regular medicines or are choosing a product for a child.

Seek emergency help for trouble breathing, swelling of the lips, tongue or throat, faintness, or rapidly worsening wheeze after a possible allergen exposure. These can accompany a severe allergic reaction and should not be managed as an isolated runny nose.

Arrange a clinical review if symptoms repeatedly disturb sleep, affect daily activities, remain unexplained or do not improve with sensible trigger avoidance and correctly used pharmacy treatment. Facial pain, swelling around an eye, persistent fever, frequent nosebleeds or discharge mainly from one nostril also warrant assessment.

Ask which features distinguish allergy from infection in your case, whether allergy testing would change management, and how long to try a medicine before judging its effect. Bring a list of suspected triggers, the timing of symptoms and every nasal product you use so the clinician can check technique and avoid duplicated ingredients.