Halitosis: new insight into a millennial old problem

Abstract

The problem of halitosis has been reported since ancienttimes. References have been found in papyrus manuscriptsdating back to 1550 BC. Hippocrates advised that any girlshould have pleasant breath, making sure always to washher mouth with wine, anise and dill seeds [1].More than50 years ago, Blackburn [2] investigated halitosis in a case-series of 73 patients affected by leukemia. He found apeculiar odor of the breath resembling that of a freshlyopened corpse. This characteristic smell is not associatedwith clinical involvement of the gum, mouth, or upperrespiratory or alimentary tract. He associated this particularsmell with the hematologic disease. Nearly 15 years ago,the role of cadaverine was pointed out as a putative com-ponent of halitosis [3]. On the contrary, putrescine, that issimilar to cadaverine, is not involved as component ofhalitosis. Cadaverine, together with putrescine, was firstdescribed in 1885 [4] by the German physician LudwigBrieger (1849–1919). Cadaverine is a toxic diamine usu-ally produced by protein hydrolysis during putrefaction ofanimal tissue. Cadaverine is also known as 1,5-pentanedi-amine and pentamethylenediamine, and represents one ofthe substances possibly implicated in establishing halitosis.Particularly, isolates of Klebsiella and Enterobacter havebeen found to emit foul odors in vitro that resemble badbreath, with concomitant production of volatile sulfides andcadaverine [5].When incubated on a sterile denture,enterobacterial isolates produce typical denture foul odor.Moreover, isolates exhibit cell-surface hydrophobic prop-erties when tested for adhesion to acryl and aggregationwith ammonium sulphate. The results, taken together,suggest that Klebsiella and related Enterobacteriaceae mayplay a role in denture malodor. However, cadaverine maybe produced by other mechanisms as well as oral bacterialgrowth.From a conventional point of view, halitosis, fetor oris,oral malodor or bad breath are the general terms used todescribe unpleasant breath emitted from a person’s mouthregardless of whether the odorous substances in the breathoriginate from oral or non-oral sources. There are fewstudies evaluating the prevalence of oral malodor in thegeneral population, with reported rates ranging from 22 tomore than 50%. In addition, approximately 50% of adultsand elderly individuals emit socially unacceptable breath,related to physiologic causes, upon arising in the morning[6]. Moreover, there are no universally accepted standardcriteria, objective or subjective that define a halitosispatient [7].Thus, this is a clinical problem as common asundervalued by clinicians who have to remember theimportance of physical examination as from the mouth’ssmell for an all-inclusive clinical decision-making. In thisissue of Internal and Emergency Medicine, Campisi et al.[8] have carried out an excellent and complete guide forapproaching the halitosis symptom. Each of us can learnfrom this interesting and in-depth review. As the authorsstate, despite its frequency, this problem is often unac-cepted and declared as taboo. However, even if nearly 90%of patients suffering from halitosis have oral causes, animportant percentage of oral malodor cases have an extra-oral etiology. They may often be referred to the category of‘‘blood-borne halitosis’’. According to the Tangerman [9]classification, this is one of the three major categoriestogether with upper respiratory tract and lower respiratorytract causes. Many organ or systemic diseases may beresponsible for ‘‘blood-borne halitosis’’ even though some