What are these conditions and what causes them?

Sinonasal disorders are the greatest cause of olfactory loss.  This area encompasses a wide range of conditions that can potentially be treated with the right medical or surgical management.

Chronic Rhinosinusitis (CRS), with or without polyps, is responsible for around 60% of cases of olfactory loss. One European study has shown that 11% of the population suffer from this.¹ The lining of the sinuses become swollen and may prevent mucus from draining, causing it to back up and get infected or in some cases the swelling bulges to form polyps that fill up the nose and sinuses, making smelling very difficult, if not impossible. As the name suggests, these problems can continue for weeks, months; even years. Other symptoms other than smell loss include nasal blockage, running of the nose (front and/or back) and facial pressure.

Nasal polyps are grape-like swellings of the nasal lining.  They can grow quite large, or in clusters, and can cause breathing difficulties, sinus pain and other issues in addition to a loss of smell.

Allergies to inhaled particles also cause swelling in the nose (allergic rhinitis).  This occurs when the immune system overreacts to allergens in the air such as pollen, animal hair or dust.  The exact relationship of allergy with CRS is unclear, but at least 25% of patients with CRS will have positive results on allergy tests. In allergic rhinitis, the swelling typically occurs in the tissue overlying the nasal turbinates (see ‘Structural Problems’ below).

Olfactory Cleft Disease describes problems – usually malformations or inflammation – linked to anatomical deformities of the olfactory cleft.  This is the cavity right at the top of each nostril in which the olfactory epithelium is situated.

Toxic Rhinitis is, as you might expect, swelling and inflammation related to airbourne toxins such as chemicals, solvents, cigarette smoke.


Structural problems

There are a number of different structural disorders of the nose.  These can be present from birth or happen later in life, perhaps as the result of an injury.

A deviated septum is one such condition, where the septum – the bone and cartilage that divide the nose in half – is displaced to one side.  This can block the flow of air up the nose and may result in a partial loss of smell but complete loss is rarely attributed to this problem.

The turbinates (or ‘nasal conchae’ as in the diagram on the right) are ridges of tissue that project from the side walls of the nose and help to filter, moisturise and warm the air that is breathed in.  They can become swollen and enlarged and block the flow of air (as per allergic rhinitis above).  They can sometimes grow much larger due to an air-filled space in the centre of them (called a ‘concha bullosa’) and thus block the nasal cavity.


Sinonasal disorders and allergies are responsible for around 70% of cases of olfactory loss

Rhinitis is the medical term for swelling in the mucous membrane of the nose


How can these conditions be treated and what are the challenges?

Sinonasal disorders are potentially the most treatable and manageable of all the causes of olfactory loss, but we know from speaking to many of our members that doesn’t necessarily happen.

A really useful document that is recommended reading for anyone affected by rhinosinusitis is the 2013 Rhinosinusitis Commissioning Guide, produced by ENT UK and the Royal College of Surgeons.  This is an evidence-based document intended for use by doctors in both primary and secondary care that provides defined treatment pathways – basically, recommendations on how patients with rhinosinusitis should be managed and treated.

Existence of the document doesn’t necessarily mean that it is utilised and followed by all doctors in the UK.  We’ve heard of instances where there is clear deviation from procedure recommended in the Commissioning Guide.

Remember that as a patient you have every right to be kept fully informed about any treatment you receive.  If you would like to know whether your doctor is following the Commissioning Guide then you have every right to ask them.


Cochrane reviews of the medical management of Chronic Rhinosinusitis

Cochrane is a global independent network of researchers, professionals, patients, carers and people interested in health.  They produce reviews that summarise the best available evidence generated through research to inform decisions about health.

Cochrane UK have reviewed a number of different options for the management of Chronic Rinosinusitis.  These have been summarised in a document aimed at informing both patients and clinicians.

What can I do?

Sinus Rinsing is highly recommended for anyone affected by a sinonasal disorder.  This can help reduce inflammation and clear out mucus from the nose and sinuses.

Relevant Research

1) Chronic rhinosinusitis in Europe–an underestimated disease

Further information and resources

Samter’s Triad

A significant proportion of people with CRS also have a condition called Samter’s Triad, now referred to as Aspirin Exacerbated Respiratory Disease (AERD). This is a combination of asthma, chronic rhinosinusitis with nasal polyps and aspirin sensitivity. People with the condition find that taking aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs), such as Ibuprofen, severely exacerbates their asthma or their nasal symptoms or both and can result in hospitalisation.

In severe cases of AERD, salicylates (related to aspirin) in the diet can also produce the same adverse effect. Significant relief can be achieved with a course of oral corticosteroids (prednisolone) but symptoms return soon after ending treatment, which ideally should not be extended due to the inevitable side effects of high blood pressure, high blood sugar and thinning of the bones.

Long-term use of topical steroids (inhaled spray/powder for asthma and nasal spray to control polyps) is the typical treatment for those with the condition, which avoids the side effects since very little of the drug is absorbed into the body beyond the nose and lungs.

In some cases, a low salicylate diet can help, but can be difficult to follow. The experience of one of our members with this is covered elsewhere on our website  and is recorded in her blog Aspirin desensitisation is another possibility, but has to be done under medical supervision since adverse symptoms must be monitored and controlled, as otherwise these could be severe.

Advice on aspirin intolerance can be found on the Allergy UK website