Rhinorrhea

Rhinorrhea (from Old Greek ῥίς — nose and ῥέω — flow) is the medical term for the excessive discharge of liquid secretion (mucus) from the nasal cavity. Rhinorrhea is not an independent disease, but is one of the most common symptoms accompanying numerous pathological conditions.

The nature of the discharge — its color, consistency, quantity and accompanying symptoms — is the most important diagnostic clue to determine the underlying cause of a runny nose. The pathogenetic basis of rhinorrhea is inflammation of the nasal mucosa, leading to hypersecretion of mucous glands and increased vascular permeability.

Aetiology and Pathophysiology

The causes of rhinorrhea are extremely varied, ranging from mild viral infections to life-threatening conditions.

The main types and their causes:

• Serous (watery) rhinorrhea: clear, copious, and liquid discharge.
  • In acute respiratory viral infections (ARVI), it is the typical initial manifestation of a “cold”.
  • Allergic rhinitis: it’s a reaction to inhalant allergens (pollen, dust, animal fur), accompanied by itching in the nose, sneezing, and lacrimation.
  • In vasomotor rhinitis, it’s a non-allergic reaction to non-specific triggers (cold air, pungent odors).
• Mucopurulent and purulent rhinorrhea mean thick, cloudy yellow or green discharge.
  • Bacterial rhinosinusitis: accession of a bacterial infection, often as a complication of acute respiratory viral infections. It is typically combined with headache and nasal congestion.
  • In the event of nasal foreign body, especially in children, the discharges are usually unilateral and bad-smelling.
• Liquor rhinorrhea (nasal liquorrhea) is an expulsion of a completely clear, water-like fluid — cerebrospinal liquor.
  • Traumatic brain injury occurs when the cranial base (e.g., sieve plate) is fractured.
  • A complication after surgery on the brain, sinuses, or cranial base. It’s an emergency condition.
  • Malignant tumors: the cause of rhinorrhea is a destruction or thinning of the bones of the cranial base and meninges, which results in cerebrospinal fluid leaking into the nasal cavity. It most often occurs with tumors of the paranasal sinuses or tumors located in the region of the anterior cranial fossa, causing destruction of bony structures and formation of a fistula.

Clinical Significance

The approach to treating rhinorrhea depends entirely on its cause. Diagnosis begins with a detailed medical history and rhinoscopy (examination of the nasal cavity).

Most cases of rhinorrhea are associated with acute respiratory infections or allergies and are not seriously dangerous. However, there are “red flags” that require immediate attention from a physician:

• Unilateral discharge, especially purulent and bad-smelling (suspected foreign body, sinusitis, or tumor).
• Rhinorrhea after head injury, especially if the discharge is watery and unilateral (suspected liquorrhea).
• Combination with severe headache, facial swelling, fever (signs of sinusitis).
• The presence of blood admixture, not associated with minor mucosal injury.

Treatment target should be the underlying disease—antiviral therapy and decongestants for acute respiratory infections, antihistamines, and nasal steroids for allergies, or antibiotics for bacterial sinusitis should be prescribed.

Differential Diagnosis

The most important and challenging task is the differential diagnosis between common watery rhinorrhea and nasal liquorrhea. Liquorrhea, unlike an allergic or viral runny nose, is usually unilateral, worsens when the head is tilted forward, and is not associated with itching or sneezing. Patients may note a salty or metallic taste in the mouth. “The gold standard” for confirming the diagnosis is to analyze secretions for the presence of beta-2-transferrin, a protein found almost exclusively in the liquor. Misdiagnosis of liquorrhea and lack of timely neurosurgical care can lead to meningitis.