Short-Term Follow-Up of Self-Isolated COVID-19 Patients with Smell and Taste Dysfunction in Greece: Two Phenotypes of Recovery

The course of anosmia and ageusia in COVID-19 patients is not yet clearly known. We present short-term follow-up data concerning mild to moderate disease in home-quarantined COVID-19 patients in Greece. Methods: We provided a symptom questionnaire and instructions for a self-administered home smell-and-taste test to 79 positive COVID-19 patients from 2 tertiary hospitals in Greece. The patients recorded their subjective symptoms before and during infection as well as 4 weeks after the diagnosis. The patients also underwent the home test during infection and 4 weeks later. Results: Twenty-nine patients (36.7%) reported a loss of smell, and 21 (27.8%) reported a loss of taste, with equal prevalences between genders. We observed 2 types of recovery, i.e., a rapid, almost complete recovery, and a second slower and partial recovery. The type of recovery was not age related. A rapid recovery was observed in two thirds of the patients, with their olfactory ratings presenting a trend towards significance in correlation with nasal obstruction. A slow recovery in olfaction was correlated with low intensity ratings in odors with a trigeminal compound. The loss of taste was more pronounced in sweet and salty intensity ratings. Conclusion: Chemosensory deficits associated with COVID-19 infection were quite frequent among the Greek patients with mild or moderate disease who, in most cases, returned to normal within 4 weeks. However, 1 in 3 patients presented with persistent olfactory and gustatory dysfunction in the short term.