What is the workup for xerostomia (dry mouth)?

Workup for Xerostomia (Dry Mouth)

A comprehensive workup for xerostomia should include a thorough medical history review, medication assessment, physical examination, and targeted laboratory testing to identify the underlying cause and guide appropriate management.

Initial Assessment

Medical History

• Review for conditions associated with xerostomia:
  • Autoimmune diseases affecting salivary glands (Sjögren's syndrome)
  • Diabetes mellitus
  • Chronic kidney disease
  • Head and neck cancer history, especially radiation treatment
  • Neurological disorders
  • Thyroid dysfunction 1

Medication Review

• Identify medications with xerostomia as side effect:
  • Diuretics
  • Calcium channel blockers
  • Lithium
  • NSAIDs
  • Anticholinergic medications
  • Antidepressants
  • Antihypertensives 1

Physical Examination

1. Oral cavity examination:

   • Assess salivary pool under tongue
   • Check for reduced salivation
   • Look for signs of scleroderma
   • Evaluate dental status (caries, periodontitis)
   • Examine for oral candidiasis 1

2. Salivary gland examination:

   • Palpate major salivary glands for enlargement, tenderness
   • Check for salivary flow from Stenson's and Wharton's ducts 1

Diagnostic Testing

Laboratory Investigations

• Basic blood tests:

  • Electrolytes and renal function
  • Thyroid function tests
  • HbA1c
  • Calcium levels
  • Complete blood count 1

• Autoimmune workup (if suspected):

  • Anti-SSA/Ro and anti-SSB/La antibodies
  • Antinuclear antibodies (ANA)
  • Rheumatoid factor 1

Specialized Testing

• Salivary flow measurement:

  • Unstimulated whole saliva collection (normal >0.1 mL/min)
  • Stimulated whole saliva collection (normal >0.5 mL/min) 2

• Salivary gland imaging (if indicated):

  • Sialography
  • Ultrasound
  • MRI of salivary glands 3

• Minor labial salivary gland biopsy (if Sjögren's syndrome suspected) 3, 4

Screening Questions

• "Do you have problems sleeping aside from needing to get up to urinate?"
• "Do you experience ankle swelling?"
• "Do you get short of breath on walking for a certain distance?"
• "Do you get lightheaded on standing?"
• "Have you been feeling excessively thirsty?"
• "Do you have any problems controlling your legs or notice tremors?" 1

Special Considerations

Cancer Survivors

For head and neck cancer survivors with xerostomia:

• Conduct complete oral and head and neck examination
• Assess risk for caries and periodontal disease
• Evaluate oral hygiene practices
• Review past dental history 1

Elderly Patients

• More thorough medication review due to higher likelihood of polypharmacy
• Assessment for age-related salivary gland changes 5

Common Pitfalls to Avoid

1. Failing to differentiate between subjective xerostomia and objective hyposalivation - Some patients report dry mouth without measurable reduction in salivary flow 4

2. Missing medication-induced xerostomia - Always perform a comprehensive medication review, including OTC medications and supplements 1

3. Overlooking systemic conditions - Xerostomia may be an early sign of undiagnosed systemic disease 3

4. Inadequate follow-up - Xerostomia can significantly impact quality of life and lead to dental complications if not properly managed 1

By following this systematic approach to evaluating xerostomia, clinicians can identify underlying causes and implement appropriate management strategies to improve patient outcomes and quality of life.