How to Approach Patients with Smell-related Complaints?

Abstract

Olfactory dysfunction (OD) affects approximately 20-30% of the general population¹ and can significantly impact daily life, including the enjoyment of food and drinks, detection of environmental hazards, social interactions and overall well-being. Olfactory dysfunction is also associated with several medical conditions, including neurodegenerative diseases (e.g., Alzheimer's and Parkinson's disease),² as well as psychiatric conditions like depression.³ Despite limited local data on prevalence and constraints in diagnostic resources and treatment options, clinicians should be prepared to evaluate patients effectively. A brief, structured clinical assessment allows early recognition, guide management, and helps identify patients who may benefit from specialist referrals.

What is Smell Loss?
Olfactory dysfunction can be classified into quantitative (hyposmia, anosmia) and qualitative disorders (parosmia, phantosmia). See Table 1.

Clinical Evaluation
A detailed history is the cornerstone of a good evaluation. Onset and duration of dysfunction are important to clarify, as sudden loss often suggests post-viral or post-traumatic causes, while gradual decline may indicate a chronic condition like neurodegenerative disease. Fluctuating olfactory changes may suggest chronic rhinosinusitis or allergic disease. Associated symptoms, such as nasal obstruction, congestion, rhinorrhea or headache; along with relevant past medical history (e.g., prior head trauma), or findings such as neurological deficits, are also important to note, as they provide additional diagnostic clues. Safety-related questions are important to ask. For example, are patients able to detect threats in their environment (e.g., smoke, gas, spoiled food)? Clinicians should also ask about appetite and any weight changes⁵ which may indicate the severity of the condition. A review of medications and medical history, including prior sinonasal surgery, head trauma, chemotherapy or illicit intranasal drug use, may help identify contributing factors.