What is Parosmia?

Parosmia is the medical term for experiencing distortions of the sense of smell.  Someone with parosmia may be able to detect odours, but the smell of certain things – or sometimes everything – is different, and often unpleasant.

These unpleasant smells are often described as being like chemicals, burning, faeces, rotting flesh, mould.  For some people they appear in response to specific odours, and for others they can be triggered by virtually any smell.

Parosmia can range from mild to severe, and can be an incredibly debilitating and depressing experience for sufferers.  We’ve heard from people who have said that their experience of parosmia was far worse than their initial loss of smell.

What is Phantosmia?

Phantosmia, as the name suggests, is the term for olfactory hallucinations, or phantom smells, that appear in the absence of any odour.  These can manifest as ‘normal’ smells – for example, being able to smell garlic when there is no garlic present – but they can also be unpleasant.

Parosmia and phantosmia are both classed as ‘dysosmia’, or qualitative disturbances of the sense of smell.

What causes these conditions?

The mechanism by which parsomia and phantosmia occur is not fully understood, but they are thought to result from damage to the olfactory receptor neurones, the cells in our nasal cavity that detect odour molecules.  It’s quite possible that damage to other areas of the olfactory system, such as the olfactory bulbs, can also cause these conditions.

Parosmia most commonly occurs when the sense of smell has been lost following a virus such as the common cold (see post-viral olfactory loss), although it can also occur as a result of head injury, exposure to toxins, diseases of the nervous system and sinus problems.

Phantosmia can occur after smell loss due to a head injury (see post-traumatic olfactory loss), but it can also be associated with viral infections, exposure to toxins, diseases of the nervous system and sinus problems.

How can these conditions be treated?

Both parosmia and phantosmia tend to occur following a loss of the sense of smell, so any treatment for the cause of this may help.  The good news is that symptoms of both conditions often decrease with time.

The Smell and Taste Clinic at James Paget Hospital has provided us with a copy of the advice sheet they give to patients.  This contains some suggestions for ways to help manage the symptoms.

Further information

Fragrance and beauty blogger Louise Woollam lost her sense of smell following a virus and then experienced severe parosmia, which she largely recovered from over time.  She documented her experience in a blog, the Parosmia Diaries, which is well-worth reading if you are suffering from this condition.