Introduction

It has long been understood that antibiotics have no role in the treatment of common colds, and yet they are often prescribed in the belief that they may prevent secondary bacterial infections. However, the likelihood of serious secondary infection, such as pneumonia and chronic sinusitis, following directly from viral upper respiratory tract infections (URTIs) is very low. There are no effective antiviral medications to treat the common cold, so the aim of treatment is to provide symptom relief. Children experience approximately six episodes of URTIs annually, reducing to two to three annual episodes for adults.1 In the UK, 34 million work days were lost in 2016 due to minor illnesses such as URTI.2

A more common complication of a viral URTI is acute purulent rhinitis (rhinosinusitis), defined as the presence of coloured discharge, from one or both nostrils, which has persisted for less than 10 days. The presence of purulent nasal discharge (or a runny nose with coloured discharge) has repeatedly been shown to be an important determinant of …