What is the appropriate workup for chronic fatigue in a 17-year-old patient?

Workup for Chronic Fatigue in a 17-Year-Old

A comprehensive workup for chronic fatigue in a 17-year-old should include quantitative fatigue assessment, thorough history, physical examination, and targeted laboratory testing to identify treatable causes before considering a diagnosis of chronic fatigue syndrome.

Initial Assessment

Quantify Fatigue Severity

• Use a standardized scale to assess fatigue severity 1:

  Fatigue Level	Severity
  0	No fatigue
  1-3	Mild fatigue (requires education only)
  4-6	Moderate fatigue (requires evaluation)
  7-10	Severe fatigue (requires prompt evaluation)

Focused History

• Duration of fatigue (must be ≥6 months for chronic fatigue syndrome) 2
• Pattern of fatigue (constant vs. intermittent)
• Presence of post-exertional malaise
• Sleep patterns and quality
• Associated symptoms:
  • Cognitive difficulties (memory, concentration)
  • Muscle or joint pain
  • Headaches
  • Sore throat
  • Tender lymph nodes
  • Unrefreshing sleep 2
• Psychosocial assessment:
  • School performance and attendance
  • Social functioning
  • Mental health symptoms (depression, anxiety)
  • Family dynamics
  • Stressors 3

Physical Examination

• Complete physical examination with focus on:
  • Vital signs (including orthostatic measurements)
  • Lymph nodes
  • Throat examination
  • Musculoskeletal assessment
  • Neurological examination
  • Signs of thyroid dysfunction 2, 4

Laboratory Investigations

• Initial laboratory studies should include:

  • Complete blood count with differential
  • Comprehensive metabolic panel
  • Thyroid-stimulating hormone (TSH)
  • Erythrocyte sedimentation rate (ESR)
  • C-reactive protein (CRP)
  • Iron studies
  • Vitamin B12 and folate levels
  • Vitamin D level
  • Urinalysis 1

• Consider additional testing based on clinical presentation:

  • Epstein-Barr virus serology
  • Celiac disease screening
  • Lyme disease testing (in endemic areas)
  • Sleep study (if sleep disorder suspected)
  • Further endocrine testing if indicated 4

Diagnostic Considerations

• Chronic fatigue syndrome diagnosis requires:
  1. Severe fatigue lasting ≥6 months
  2. Presence of at least four additional symptoms:
     • Post-exertional malaise
     • Unrefreshing sleep
     • Impaired memory/concentration
     • Muscle pain
     • Multi-joint pain
     • New headaches
     • Sore throat
     • Tender lymph nodes 2, 3
  3. Exclusion of other medical and psychiatric causes

Management Approach

• If moderate to severe fatigue is identified, implement:
  • Structured exercise program (150 minutes moderate aerobic exercise weekly) 1
  • Cognitive behavioral therapy 2, 3
  • Sleep hygiene education
  • Regular schedule of activity and rest 5
  • Address any identified contributing factors (anemia, thyroid dysfunction, etc.)

Common Pitfalls to Avoid

• Attributing fatigue solely to one cause without comprehensive evaluation
• Overlooking psychological factors
• Dismissing fatigue as "normal" when it significantly impacts quality of life
• Prescribing exercise without proper assessment of underlying conditions
• Failing to recognize medication side effects as potential causes of fatigue 1

Follow-Up

• Schedule regular follow-up visits
• Reassess fatigue levels using standardized scale
• Adjust treatment plan based on response 1
• Continue to monitor for development of new symptoms that might suggest alternative diagnoses

The prevalence of chronic fatigue syndrome in adolescents is relatively rare (0.11-1.29%) compared to symptomatic fatigue, but it can have significant impacts on academic and social development due to school absence 3. Early diagnosis and appropriate management are essential for improving long-term outcomes.