What is the appropriate workup for a patient presenting with night sweats?

Diagnostic Workup for Night Sweats

The appropriate workup for night sweats should include a focused history and physical examination followed by targeted laboratory and imaging studies based on clinical suspicion, with initial screening tests including complete blood count, tuberculosis testing, HIV testing, thyroid function tests, C-reactive protein, and chest radiography. 1

Initial Assessment

Detailed History

• Onset, pattern, duration, and severity of night sweats
• Associated symptoms:
  • Fever, weight loss, cough (suggesting infection or malignancy) 2
  • Alcohol intolerance, pruritus, fatigue (suggesting lymphoma) 2
  • Reflux symptoms (suggesting GERD) 1
  • Respiratory symptoms like dyspnea, wheezing (suggesting pulmonary disease) 2
• Medication review (antihypertensives, antipyretics, SSRIs) 3
• Substance use (alcohol, drugs) 3
• Risk factors for HIV and tuberculosis 2

Physical Examination

• Complete lymph node examination (cervical, axillary, inguinal) 2
• Cardiopulmonary assessment
• Abdominal examination for hepatosplenomegaly
• Skin examination for rashes or lesions

First-Line Laboratory and Imaging Studies

1. Complete blood count with differential 1, 3
2. Erythrocyte sedimentation rate (ESR) and/or C-reactive protein (CRP) 1, 2
3. Tuberculosis testing (PPD or interferon-gamma release assay) 1, 3
4. HIV testing 1, 3
5. Thyroid-stimulating hormone (TSH) 1, 3
6. Chest radiography 1, 3

Second-Line Investigations (Based on Clinical Suspicion)

For Suspected Malignancy

• PET/CT scan (particularly if lymphoma is suspected) 2
• CT scan of chest, abdomen, and pelvis 1, 3
• Consider bone marrow biopsy if blood counts are abnormal 1, 3

For Suspected Infection

• Blood cultures if febrile
• Sputum cultures if respiratory symptoms present 2
• Additional testing for specific infections based on risk factors and exposure history 2

For Other Conditions

• Polysomnography if sleep apnea suspected 1
• Gastroesophageal reflux evaluation if symptoms suggest GERD 1
• Liver function tests if hepatic disease suspected

Special Considerations

For Patients with HIV Risk Factors

• HIV testing should be offered to all patients with night sweats who have risk factors for HIV infection 2
• In communities with high HIV prevalence (>1%), routine HIV testing should be considered for all patients with night sweats 2

For Patients with TB Risk Factors

• More aggressive TB workup including sputum cultures and possibly bronchoscopy 2
• Consider chest CT if chest X-ray is negative but clinical suspicion remains high 2

Management Approach

1. If a specific cause is identified during initial evaluation, provide targeted treatment
2. If initial evaluation is negative but symptoms persist:
   • Consider second-line investigations based on clinical suspicion
   • Reassess after 4-8 weeks 1
3. If all investigations are negative:
   • Provide reassurance that night sweats alone do not indicate increased mortality risk 1, 4
   • Consider symptomatic management
   • Continue monitoring for new symptoms

Common Pitfalls to Avoid

• Failing to consider medication side effects as a cause of night sweats
• Overinvestigation when clinical presentation suggests a benign cause
• Underinvestigation when red flag symptoms (weight loss, fever, lymphadenopathy) are present
• Neglecting to consider rare but serious causes like pulmonary embolism in post-surgical patients 5

Remember that while serious conditions like malignancy and tuberculosis are important considerations, most patients with night sweats in primary care settings do not have a serious underlying disorder 1, 4.