Cluster Headache is Still Lurking in the Shadows.

Cluster headache, apart from its legendary reputation as the most violent headache that can exist, suffers from an average 60-month delay in diagnosis. The simplicity of the clinical manifestations, although dramatic, makes this delay inexplicable. The education of emergency department physicians and various specialists not specifically dedicated to headaches allows cluster headache to remain in a lurking position with flourishing periods of disease that are often unpredictable in both onset and disappearance. Older drugs have always shown high efficacy but also an equally high rate of adverse events, often discouraging their appropriate use. The availability of a new drug class such as monoclonal antibodies for calcitonin gene-related peptide or its receptor (CGRP(r)), which have already been efficient for migraine, shows a jeopardized geography of access in the world, and this favors the progression of the episodic form into chronic and of the chronic into refractory.