Headaches are common in children, increasing in incidence from early childhood to adolescence. They account for 0.7% to 1.3% of all paediatric emergency department visits.   Headaches may be classified as primary or secondary.  Primary headaches include migraine, tension-type, cluster, as well as the new daily persistent headache. Secondary headaches are symptomatic of an underlying intracranial or medical condition that requires treatment. The initial assessment of acute headache aims to determine whether there is a secondary cause for headache that requires urgent intervention.
Headache may be classified in terms of time course.
A single episode of headache pain without prior headaches.
May represent the first or an unusually severe form of primary headache.
May suggest a new acute secondary cause for headache that, therefore, requires evaluation.
Acute recurrent headache
Stereotyped headaches separated by headache-free periods.
Most suggestive of a primary headache disorder, especially if the pattern has persisted for a long period.
May also occur in secondary headache, as with intermittent elevation in intracranial pressure.
Chronic progressive headache
A gradual increase in headache.
Suggestive of an expanding intracranial lesion.
Of children with brain tumours, 62% have headache prior to diagnosis, and 98% have at least one neurological symptom or abnormality on examination. 
The most common symptoms include nausea or vomiting, difficulty walking, visual symptoms, focal weakness, or personality change. 
The most common signs include optic nerve oedema, abnormal eye movements, ataxia, abnormal reflexes, and visual field or acuity defects. 
Chronic non-progressive headache
Constant steady headache.
May be due to a chronic type of primary headache or similar secondary aetiologies.
A: At least 5 attacks fulfilling criteria B-D
B: Headache attacks lasting 2 to 72 hours (when untreated or unsuccessfully treated) (note: compared with 4 to 72 hours in adults)
C: Headache having at least 2 of the following characteristics:
Unilateral location, may be bilateral, frontotemporal*
Moderate or severe pain intensity
Aggravation by or causing avoidance of routine physical activity (e.g., walking, climbing stairs)
D: During the headache, at least 1 of the following:
Nausea or vomiting
Photophobia and phonophobia, which may be inferred from behaviour
E: Not attributable to another disorder.
*The ICHD-3 classification notes that migraine headache in children and adolescents (aged under 18 years) is more often bilateral than is the case in adults; unilateral pain usually emerges in late adolescence or early adult life. Migraine headache is usually frontotemporal. Occipital headache in children is rare and calls for diagnostic caution. 
Diagnosis of migraine with aura requires:
A: At least 2 attacks fulfilling the criteria B and C
B: 1 or more of the following fully reversible aura symptoms**:
3. Speech and/or language
C: At least 3 of the following 6 characteristics:
1. At least 1 aura symptom spreads gradually over 5 minutes
2. Two or more aura symptoms occur in succession
3. Each individual aura symptom lasts 5-60 minutes
4. At least 1 aura symptom is unilateral
5. At least 1 aura symptom is positive
6. The aura is accompanied, or followed within 60 minutes, by headache
D: Not attributable to another disorder.
**The ICHD-3 classification notes that in children and adolescents, less typical bilateral visual symptoms occur that may represent an aura. 
Department of Child Neurology
Johns Hopkins Hospital
CBO declares that he has no competing interests.
Dr Christopher B. Oakley would like to gratefully acknowledge Dr Nicholas S. Abend and Dr Daniel J. Licht, the previous contributors to this monograph. NSA and DJL declare that they have no competing interests.
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