New daily persistent headache

New daily persistent headache (NDPH) is a rare headache syndrome affecting both paediatric and adult populations. In the latest revision of International Classification of Headache Disorders, 3rd edition (ICHD-3 beta), it is defined by the onset of daily and unremitting headaches within 24 hours lasting for more than 3 months. Common triggers include flu-like symptoms and stressful life events; however, the pathophysiology is largely unknown. Regarding headache features, in the ICHD-3 beta, migrainous features are allowed in comparison with ICHD-2. Different triggers and heterogeneous clinical presentations suggest that NDPH is more likely a syndrome, rather than a disease entity. Secondary aetiologies must be carefully excluded, especially meningitis, high and low intracranial pressure headaches, medication overuse headache, or reversible cerebral vasoconstriction syndrome. There are no randomized placebo-controlled trials for NDPH; thus, the treatment is mostly empirical. Most patients have persistent headache despite treatment, but approximately one-quarter of them reached remission, usually within 24 months. However, a subgroup of those who reached remission initially might experience relapse after months or years free from pain.