What is the most likely etiology of a child presenting with sudden onset of severe headache?

The most likely etiology for a child presenting with a sudden onset of severe headache is indeed conditions like migraines, intracranial hemorrhages, or meningitis. Severe headaches that appear suddenly and are described as intense can indicate serious underlying conditions.

Migraines can cause significant pain and may occur suddenly in children, exhibiting symptoms such as nausea and sensitivity to light. Intracranial hemorrhages, which may stem from trauma or other health issues, present with severe headache as a critical symptom. Meningitis, an inflammation of the protective membranes covering the brain and spinal cord, also leads to sudden, severe headaches and often includes additional symptoms like fever and neck stiffness.

Other options, such as simple tension headaches due to lack of sleep, while possible, typically present gradually rather than suddenly and do not usually result in an acute crisis. Allergic reactions, though capable of causing discomfort, do not usually manifest as sudden severe headaches. Similarly, vision problems or eye strain can lead to headaches but are unlikely to cause the intense and abrupt headache described in this scenario. Therefore, when considering the context of a child's sudden, severe headache, conditions like migraines, intracranial hemorrhages, or meningitis must be the primary considerations due to their urgency and