TABLE 9–1.

Potential Red Flags for Serious Causes of Headache Organized by the Mnemonic SNOOP4Y^a

Red Flag	Significance
Systemic signs/symptoms
Fever, acute symptoms	Infections ranging from minor to serious35 are the most common cause of headache in children in the emergency department
Head trauma	Relatively common cause for headache in the emergency department
Vomiting	Consistent with migraine38 but also a risk factor for brain tumors39
Weight loss	Can be a symptom of malignancy
Comorbidities	Many systemic illnesses, including rheumatologic, oncologic, vascular, and hematologic conditions; genetic syndromes; and abnormalities of the immune system predispose to other serious causes for headache
Medications	Headache can be a medication side effect40
Neurologic signs/symptoms	Abnormal gait, ataxia, papilledema, changes in personality/behavior/cognition, visual disturbances/eye movement abnormalities, and seizure39 are red flags for serious secondary headache
Onset sudden	Thunderclap onset of headache in which pain peaks instantly is rare in children but can signal serious causes such as cerebral hemorrhage or reversible cerebral vasoconstriction syndrome; the full range of differential diagnosis from adults with thunderclap headache should be considered, and imaging should be pursued
Onset in sleep/early morning	Headache causing a child to awaken from sleep or occurring early in the morning has been associated with intracranial lesions41 and can be suggestive of sleep apnea and other sleep disorders42; however, this diurnal pattern is also common in primary headache disorders43
Positional exacerbation
Worse upright	Headache that resolves when supine and worsens immediately upon standing or slowly throughout the day can suggest spontaneous intracranial hypotension or postural tachycardia syndrome33
Worse supine	Consider increased intracranial pressure from tumor or idiopathic intracranial hypertension
Precipitated by Valsalva	Brief headaches triggered by Valsalva maneuvers can signal intracranial abnormalities; headache triggered by cough along with signs/symptoms of brainstem/cerebellum/cervical spinal cord dysfunction38 may suggest Chiari malformation (although Chiari malformation may be found incidentally with other headaches and is of varying significance)
Parents (lack of family history)	Several studies have found that lack of family history of headaches is associated with higher odds of having a serious cause of headache in children39; most children with migraine have a family history of migraine, although the parent(s)/guardian(s) may not be aware of the diagnosis
Progressive or new	Significant change in the headache pattern, new headache, or progressively escalating headache raises the level of concern for secondary cause44; however, many new-onset headaches are not caused by structural brain abnormalities44 and may be attributed to relatively benign causes such as viral infections; furthermore, studies have used different cutoff points from days to months45 when trying to determine when a "recent-onset” headache is worrisome, so the newness of the headache must be interpreted with the presence or absence of other headache features
Young age	Some studies have found that children of younger age (defined as either ≤5 years45,46 or <7 years39) were more likely to be diagnosed with a life-threatening headache, whereas other studies have refuted that concern44

^aThe mnemonic SNOOP4Y is adapted from the SNOOP4 used in adults.³⁷