Case Presentation: CASE PRESENTATIONA 78-year-old male with a medical history of uncontrolled diabetes mellitus, hypertension, and hyperlipidemia presented with a two-year history of anosmia and ageusia, significantly affecting his quality of life. These symptoms began shortly after a presumed COVID-19 infection, initially attributed to post-viral sequelae. Despite multiple interventions, including evaluation by otolaryngology and use of a taste-testing kits, his symptoms persisted without improvement. The patient expressed growing frustration and reported a profound loss of appetite, leading to unintentional weight loss and concerns about potential nutritional deficiencies.In addition to the physical symptoms, the patient experienced significant psychosocial distress. He described avoiding meals with family and friends, due to embarrassment and a lack of enjoyment. He expressed that the persistent anosmia and ageusia eroded his quality of life and his ability to engage in once-pleasurable activities. As indicated, further workup revealed a normal metabolic profile and heavy metal panel, including arsenic, lead, and mercury levels. However, serum zinc was found to be low at 57 mcg/dL. Interestingly, the patient had been taking zinc supplements, but concurrent intake with meals and other medications likely impaired its absorption.
Discussion: Anosmia and ageusia are multifactorial conditions often associated with infectious, neurologic, or metabolic etiologies. The differential diagnosis for anosmia includes a wide range of etiologies such as post-viral olfactory dysfunction, sinonasal disorders (e.g., chronic rhinosinusitis, nasal polyps), neurologic conditions (e.g., Parkinson’s disease, Alzheimer’s disease), nutritional deficiencies (Ex: zinc, vitamin B12), medication side effects, and exposure to environmental toxins. In this case, the initial onset of symptoms following a suspected COVID-19 infection highlighted post-viral olfactory dysfunction as a possible mechanism. However, the protracted course and lack of response to standard interventions necessitated further evaluation. The eventual identification of hypozincemia as a contributing factor underscores the importance of micronutrient evaluation in persistent anosmia and ageusia. Zinc is critical for the function and regeneration of gustatory and olfactory receptors, and deficiency can impair these sensory modalities. In this patient, the suboptimal zinc absorption likely resulted from concurrent intake with food and medications, which are known inhibitors of zinc bioavailability. Although zinc supplementation is a recognized treatment, the patient’s improper administration underscores the need for patient education regarding optimal supplementation practices.
Conclusions: This case highlights the importance of a thorough and nuanced approach to evaluating persistent anosmia and ageusia, especially in the context of presumed post-viral sequelae. While COVID-19-associated olfactory and gustatory dysfunction is well-documented, this case demonstrates that overlapping etiologies, such as hypozincemia, must also be considered. Correcting zinc deficiency through optimized supplementation practices may offer symptom relief and improve quality of life for affected individuals. Furthermore, this case emphasizes the value of collaborative care and patient advocacy in uncovering less obvious underlying causes of complex clinical presentations.