Differential Diagnosis for Severe Intolerance to Odours

• Single Most Likely Diagnosis
  • Migraine: Some people with migraines may experience severe sensitivity to smells, which can trigger or worsen migraine attacks. This condition is relatively common and can significantly impact quality of life.
• Other Likely Diagnoses
  • Anxiety Disorders: Conditions like generalized anxiety disorder or panic disorder can lead to heightened sensitivity to environmental stimuli, including odours. Stress and anxiety can exacerbate sensitivity.
  • Sinusitis or Rhinitis: Inflammation of the sinuses or nasal passages can affect the sense of smell, leading to increased sensitivity to odours. These conditions are common and can cause significant discomfort.
  • Multiple Chemical Sensitivity (MCS): A condition characterized by adverse reactions to low levels of chemicals, including those found in everyday products, which can manifest as severe intolerance to various odours.
• Do Not Miss Diagnoses
  • Temporal Lobe Epilepsy: Although rare, temporal lobe epilepsy can cause unusual sensitivities, including to smells, as part of its aura or seizure activity. Missing this diagnosis could lead to untreated seizures.
  • Brain Tumors: Certain brain tumors, especially those affecting the temporal lobe or olfactory system, can cause changes in smell perception, including heightened sensitivity to odours. Early detection is crucial for treatment and prognosis.
• Rare Diagnoses
  • Hyperosmia: A rare condition where the sense of smell is significantly more sensitive than average. This can lead to severe intolerance to odours due to an exaggerated response.
  • Phantosmia: Involves smelling odours that aren't present, which can be distressing and might be perceived as intolerance to certain smells. This condition can be associated with neurological disorders or damage to the olfactory system.
  • Kallmann Syndrome: A genetic disorder that affects the development of the olfactory bulb and gonadotropin-releasing hormone production, leading to anosmia (loss of smell) or, less commonly, hyperosmia. It's a rare condition that could potentially cause unusual smell perceptions.