Runny nose: which clues suggest an allergy rather than a cold?

Both a cold and allergic rhinitis can cause a runny or blocked nose. Repeated episodes, the circumstances and other symptoms help distinguish them. These clues help you describe the situation to a professional; they do not establish your own diagnosis.

Bursts of sneezing, an itchy nose or throat and itchy or watery eyes can fit an allergy. A clear discharge without fever can also suggest one, but some cold symptoms overlap.

A cold is a viral infection. The nasal discharge can become thicker and yellow-green over several days. This colour alone does not prove a bacterial infection or establish that an antibiotic is needed.

Note whether episodes happen near an animal, in a dusty place or with a particular exposure. Not all allergic rhinitis is seasonal: dust mites, animals and mould can be involved. A doctor decides whether allergy testing is useful.

Have new breathing difficulty assessed promptly. Call 15 or 112 for severe difficulty breathing, blue lips or an inability to finish sentences. Do not dismiss these signs as just a blocked nose.

To prepare for advice, explain when the runny nose started, relevant exposures and any products already used. Seek assessment if repeated episodes have a lasting effect on daily life. Our Mon bilan prévention page describes a separate prevention approach, distinct from assessing these symptoms.