A Case of Post-traumatic Parosmia that Resolved after Five Years

<p>Post-traumatic olfactory dysfunction is known to have a poor prognosis. Traumatic olfactory dysfunction is commonly associated with parosmia, which is an often neglected symptom due to difficulty with its assessment using standard olfactory testing. We report a case of a patient diagnosed with post-traumatic olfactory loss and parosmia. Olfactory loss recovered within one year, but parosmia persisted for five years before disappearing.</p><p>The patient was a 41-year-old woman who fell from a 2-meter-high wall and injured her right occipital area. A few days later, she noticed a decreased sense of smell and visited our department. An intravenous olfactory test and T&T olfactometry showed olfactory loss. She was treated with olfactory stimulation and followed up with T&T olfactometry, Open Essence, a Visual Analogue Scale (VAS), and the Self-Administered Odor Questionnaire (SAOQ). Approximately one year after the injury, her sense of smell was rated as cured by T&T olfactometry, but showed no improvement on VAS or SAOQ, and parosmia remained. The patient continued olfactory stimulation at home, and approximately 5 years after the injury parosmia disappeared, with VAS and SAOQ also showing significant improvement.</p><p>Qualitative olfactory dysfunction such as parosmia is difficult to assess with standard olfactory tests, but patients with parosmia suffer from a significant loss of quality of life. Olfactory identification tests and subjective symptom-based evaluations such as VAS and SAOQ may better reflect the subjective symptoms of parosmia, in addition to standard olfactory tests. Post-traumatic parosmia should also be approached with the understanding that this condition may undergo long-term changes.</p>