Bad Breath
This common symptom is usually caused by poor dental hygiene. As a presenting complaint it is seen far more often by dentists than other clinicians. It may be detected when examining a patient for an unrelated complaint, and rarely but significantly can herald serious pathology.
Differential diagnosis
Common Diagnoses
- Poor Dental Hygiene
- Heavy Smoking
- Gingivitis (Including Acute Necrotising Ulcerative Gingivitis [ANUG], Acute and Chronic Gingivitis)
- Excess Alcohol Intake (Acute and Chronic)
- Discharging Dental Abscess
Occasional Diagnoses
- Ketohalitosis of Starvation: Especially in People Using High-Protein, High-Fat, Low-Carbohydrate Weight Reduction Diet Regimens (and Pre-Operatively Starved Patients)
- Drugs, e.g. Disulfiram
- Acute or Chronic Sinusitis
- Subjectively Perceived (Non-Existent) Halitosis (Sometimes a Form of somatisation)
- GORD or Acute Gastroenteritis with Reflux of Gas
Rare Diagnoses
- Bronchiectasis
- Liver Failure: Hepatic Foetor is Said to Smell Like a Freshly Opened Corpse; This is Due to Mercaptans in Expired Air
- True Delusional Subjective Halitosis as Part of Psychiatric Condition, e.g. Severe Depression with Nihilism, Psychotic Illnesses
- Rare Oral or Nasal Conditions (e.g. Pyogenic Granuloma, Discharging Sinus from Abscess)
Ready reckoner
Key distinguishing features of the most common diagnoses
| Poor Dental Hygiene | Heavy Smoking | Gingivitis | Excess Alcohol | Dental Abscess | |
|---|---|---|---|---|---|
| Painful Face/Jaw | No | No | Possible | No | Yes |
| Bleeding Gums | Possible | No | Yes | Possible | Possible |
| Facial Swelling | No | No | No | No | Yes |
| Dental Staining | Yes | Possible | Possible | No | Possible |
| Intoxication/Stigmata of Chronic Alcohol Abuse | No | No | No | Yes | No |
Possible investigations
- It is unlikely that primary care would initiate any investigations other than LFT if alcohol is a likely aetiology, or liver failure is suspected. CXR may be helpful if bronchiectasis is a possibility. However, dentists may carry out the following investigations:
- Plaque and bleeding indexes: For oral hygiene.
- Basic periodontal examination: Measurement of pocket depth between gums and teeth carried out with a specially marked probe.
- Oral pantomograph X-ray to investigate general state of teeth.
Top Tips
- The vast majority of cases will involve oral hygiene. Be certain to exclude this, and other physical causes, before deciding that the halitosis is entirely subjective. As with other forms of somatisation, active management – with a psychiatric referral if necessary – is preferable to sending the patient away, only to return to make more appointments.
- If no obvious oral cause is found initially, extend the history and examination to include the respiratory and gastrointestinal systems.
- ANUG is a ‘spot diagnosis’ – the stench usually precedes the patient by some distance.
Red Flags
- In the absence of an obvious cause, do not neglect to examine the head and neck including the buccal cavity and nasal airway. Failure to do so could mean that a serious local cause is missed.
- Do not overlook alcohol abuse as a possible underlying cause.
- If the impact of the symptom seems out of all proportion to any objective sign of a problem, consider depression.