Parosmia and phantosmia
When familiar smells become distorted or unpleasant after smell loss. Common after viral infection, often improves with time, and sometimes responds to specific treatment.
Parosmia is a distortion of smell: a familiar smell, often food or perfume, comes through as something different and frequently unpleasant. Coffee, onions, meat and chocolate are typical triggers. Phantosmia is the related experience of smelling something that is not there, often described as smoke, chemical or burnt. Both usually follow a period of reduced or absent smell, most commonly after a viral infection or head injury, and most often during recovery rather than at the start.
How it presents
- Foods you used to enjoy now taste rotten, chemical or "sewage-like"
- Coffee, onions, garlic, meat and chocolate are particularly common triggers
- Soaps, deodorants, toothpaste and partners can smell wrong
- Periods of normal smell can alternate with parosmic episodes
- Phantom smells (phantosmia) such as smoke or burning, with nothing present
The "disgust response"
Parosmia frequently triggers an out-of-proportion disgust response: nausea, food avoidance, weight loss, and significant distress at everyday meals. This is a biological reaction, not weakness. The smell system is closely wired to the parts of the brain that protect us from spoiled food, so a misfired signal lands hard. Understanding that the disgust is the alarm rather than the food helps some people manage it.
How long it lasts
Parosmia after viral infection most often appears 2 to 6 months after the original smell loss, when the olfactory neurons are reconnecting. For many people it improves over months; some still notice occasional distortions a year or two later. Earlier smell training and good general nasal care seem to be associated with better recovery, but the natural history is variable. Persistent parosmia beyond two years is unusual but not unheard of.
What helps day to day
- Identify your particular triggers and adapt around them; many people find chicken, pasta, dairy and eggs tolerable when coffee and meat are not
- Cold foods tend to be less aromatic and easier than hot ones; smoothies, dairy, plain breads and rice can sustain calories
- Continue smell training, which may help retrain the system; see the smell training guide for the full method
- Treat any underlying nasal inflammation; a blocked nose worsens distortions
- Recognise the disgust response for what it is and, where possible, eat in well-ventilated spaces away from the worst triggers
Medication for parosmia
There is no medication that reliably treats parosmia, but there is emerging interest in specific drugs in selected patients. The anticonvulsant gabapentin has been studied for its effect on the disgust component of parosmia, with mixed but interesting early results. Sodium citrate nasal rinses and theophylline have also been studied. None of these is a routine treatment, and any decision is taken case by case after assessment.
When to seek assessment
- Parosmia persisting more than three months that is disrupting eating or daily life
- Phantom smells, especially if accompanied by headache, vision change or seizures (these need urgent assessment, since rare causes include intracranial conditions)
- Smell distortion alongside a blocked nose, facial pressure or nasal discharge (treatable nasal inflammation may be a factor)
- Significant weight loss or low mood related to the loss of food enjoyment
Mr Gane has researched and treated post-viral smell disorders since the start of the COVID-19 pandemic. Assessment is a careful history, a full examination of the nose, and where appropriate formal smell testing and imaging. Treatment depends on the cause and may include nasal anti-inflammatory treatment, structured smell training, and selected medication in resistant cases.
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This guide is general information and not a substitute for individual medical advice. Contact the practice if you have questions about your own care.