Halitosis in patients living with chronic kidney disease: An updated narrative review

This narrative review summarized the latest findings on halitosis in patients living with chronic kidney disease (CKD), including its epidemiology, etiology, classification, contributing compounds, diagnosis and treatment. Halitosis is present in 30-57% of patients living CKD in most reports. Accumulated metabolites in the blood circulation and multiple oral changes secondary to CKD are its main causes. It consists of intra-oral halitosis and extra-oral halitosis according to etiology. Ammonia, dimethylamine, trimethylamine, hydrogen sulfide, methyl mercaptan and dimethyl sulfide are its main contributing compounds. A combination of the subjective organoleptic test and the objective OralChroma breath test is essential for its diagnosis. Also, it is recommended that the organoleptic test and OralChroma breath test be performed for both mouth and nose breath. By comparing these two sets of results, clinicians can identify which subtype of halitosis is predominant in an individual patient. Kidney replacement therapies and antibiotics appear to be effective to treat this condition through reducing accumulated metabolites in the blood circulation.