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Nasal Discharge (Rhinorrhoea)


Nasal discharge is a sign and symptom of all causes of rhinitis. It also occurs in tumours of the nose and in CSF rhinorrhoea. Below is a short guide to nasal discharge and its causes.


Rhinitis is an inflammatory condition of the nasal mucosa. There are a number of causes for this inflammation and the three most important are listed below:

  1. Infective rhinitis

  2. Allergic rhinitis

  3. Vasomotor rhinitis (an old term)

In infective rhinitis, when the cause is viral, the nasal discharge is typically thin and clear. This changes to a thicker clear mucus after a few days and then turns creamy / green as bacterial superinfection sets in. The discharge passes to the post nasal space and is swallowed or is blown out of the nose.

There is another form of infective rhinitis, in children, usually. When a foreign body (especially organic, paper or foam) has been pushed up the nose by a child it provokes bacterial infection within the nose. This causes a unilateral purulent nasal discharge that is often foul smelling. Indeed a unilateral discharge in a child must provoke a search for a foreign body. This may be done under general anaesthetic if necessary.

In allergic rhinitis the discharge is thin and provoked by an allergen e.g. grass pollen. However, it may be present all year if the allergen is present throughout the year e.g. house dust mite.

Vasomotor rhinitis causes a thin discharge that is provoked by smoke, perfume, cold air and many others.


Tumours in the nose are extremely uncommon. When they do occur they tend to produce a thin, blood stained discharge.

CSF Rhinorrhoea

CSF leaks into the nose from the ethmoid or sphenoid sinuses, the cribriform plate and from the ear via the Eustachian tube. Generally it follows trauma such as in a Road Traffic Collision but may be a sequel of sinus surgery. Often it is idiopathic.

The discharge is thin and clear. It is made worse by bending and straining and it may be unilateral.

Testing for it can be difficult because of the small volume that is often present. Tests of glucose concentration used to be important but now assays for beta 2 transferrin are available. Localising the leak requires intrathecal fluorescein which can be seen to ooze into the nose from the site of the leak. CT scanning is usually performed as this may show the site of the leak and assists in surgical planning.

A patient comes to you with nasal discharge...

As always a history and examination will guide you.


Is the discharge unilateral? If so, this could be a foreign body, unilateral sinusitis or CSF leak. What is the discharge like? Is it thin, clear and worsened by bending down? If so, CSF leak is a possibility. If it is unilateral, mucous and coloured there is an infection in the nose or sinus. If the patient's nose smells bad suspect a foreign body (especially if it is a child) or dental disease causing unilateral sinusitis.

Of course, each of these diseases can be explored more fully by history taking.

If bilateral discharge is present consider rhinitis in its various forms or chronic rhinosinusitis.

Treatment will be directed at the cause. CSF leaks need referral for specialist opinion and foreign bodies are often difficult to get out of the nose in Primary Care. Please review management of rhinitis and rhino sinusitis on their relevant pages.

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