Laboratory Testing for Headaches in an 11-Year-Old Female
Laboratory tests are generally NOT indicated for pediatric headache evaluation unless specific red flags suggest a secondary cause requiring blood work. 1, 2
When Laboratory Tests Are NOT Needed
For primary headaches (migraine, tension-type) with a normal neurological examination and no red flags, no laboratory testing is required. 1, 2 The diagnostic approach should focus on:
- Complete neurological examination including vital signs with blood pressure measurement, cranial nerve assessment, fundoscopic examination for papilledema, motor/sensory testing, cerebellar function, gait evaluation, and mental status 2
- Blood pressure measurement is mandatory, as hypertension can indicate increased intracranial pressure 2
- Fundoscopic examination is essential and should never be skipped, as papilledema indicates increased intracranial pressure 2
When Laboratory Tests ARE Indicated
Laboratory testing should be obtained only when specific secondary headache causes are suspected based on clinical findings:
Infection-Related Headaches
- Complete blood count (CBC) if fever, meningeal signs, or systemic infection suspected 3, 4
- Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) if temporal arteritis considered (though rare in this age group) 3, 4
- Blood cultures if bacteremia suspected 3
Endocrine/Metabolic Causes
- Thyroid function tests if symptoms suggest thyroid dysfunction 3
- Basic metabolic panel if dehydration, electrolyte imbalance, or renal issues suspected 3
Hematologic Causes
- CBC with differential if anemia, thrombocytopenia, or leukemia suspected 3, 5
- Sickle cell screening if not previously done and patient has risk factors, as stroke is a concern in sickle cell disease 2
Pseudotumor Cerebri (Idiopathic Intracranial Hypertension)
- No specific laboratory tests diagnose this condition, but workup may include evaluation for secondary causes such as vitamin A toxicity or endocrinopathies 1, 2
Critical Red Flags Requiring Immediate Evaluation (Not Necessarily Labs)
These findings mandate urgent neuroimaging rather than laboratory testing:
- Papilledema on fundoscopy indicates increased intracranial pressure 2
- Abnormal neurological findings (94% of children with brain tumors have abnormal neurological findings at diagnosis) 2
- Sudden severe "thunderclap" headache suggests subarachnoid hemorrhage 2, 3
- Headache worsened by Valsalva maneuver suggests Chiari malformation or increased intracranial pressure 2, 3
- Progressive or worsening headache during observation 2
- Altered mental status or seizures 2
Common Pitfalls to Avoid
- Do not order routine laboratory tests without specific clinical indications, as the yield is extremely low in children with normal examination and no red flags 1, 2
- Do not skip fundoscopic examination, as it is essential for detecting increased intracranial pressure and has higher diagnostic value than routine labs 2
- Do not diagnose "sinus headache" without considering migraine first, as 62% of pediatric migraineurs have cranial autonomic symptoms (rhinorrhea, nasal congestion) that mimic sinusitis 2
- Do not order neuroimaging without red flags, as the diagnostic yield is less than 1% for clinically significant findings in children with normal examination 2