Smell disorders: A study of 132 patients from the first smell and taste clinic of Thailand

Objective: To investigate types and possible causes of smell disorders in patients who attended the Smell and Taste Clinic, Siriraj Hospital. Material and Method: Medical records of patients with smell disorders who attended the Smell and Taste Clinic, Siriraj Hospital between July 2002 and August 2005 were reviewed for gender, age, duration of complaint, severity (hyposmia or anosmia), and previous medical illnesses (e.g. upper respiratory tract infection (URI), head injury, sinonasal problems, etc). All patients had complete physical examination, nasal endoscopy, and phenyl ethyl alcohol (PEA) olfactory threshold test. Results: One hundred and eighty eight patients' medical records were reviewed. Smell disorders were confirmed in 132 cases (male = 58, female = 74). Nearly an equal number of anosmia and hyposmia cases were found (50.8% and 49.2% respectively). Possible causes of smell disorders were categorized as follows: sinonasal disease (SND) (66.7%), head injury (12.1%), idiopathic cause (10.6%), URI (6.8%), congenital cause (3%), and others (0.8%). SND was the most common cause of smell disorders despite different age groups and duration of smell disorders. PEA test scores were higher in head injury and idiopathic groups compared with those in SND and post URI groups. Conclusion: The present data showed that SND was the major cause of smell disorders in every age group and in each duration group followed by head injury, idiopathic cause, and URI respectively. Therefore, nasal endoscopy is highly recommended for every patient with smell disorders.