Pediatric nummular headache: review of the literature and a case series with nosographic considerations

Abstract

Background Nummular headache (NH) is a rare, often underdiagnosed form of primary headache, characterized by pain localized to a well-circumscribed area of the scalp. Although well documented in adults, its presentation in pediatric age is still poorly understood and rarely described. Methods The narrative review synthesizes the few pediatric NH cases reported in the literature. Further we describe our small case series of six pediatric patients (age 9–17 years) diagnosed with NH. For each case, the following were evaluated: clinical features, age of onset, localization and form of pain, associated symptoms, family history, response to treatments and neuroradiological findings. Diagnoses were compared with ICHD-3 criteria and with data present in the literature. Results Five patients presented with episodic NH, one with a continuous form. The painful area ranged from 1 to 4 cm in diameter, with round, oval and rectangular shapes. Four reported migraine-like symptoms. In one case NH was secondary to Langerhans cell histiocytosis. In two patients, a rectangular-shaped area of pain was observed, suggesting the need to review the diagnostic criteria. Conclusions This case series highlights the clinical heterogeneity of NH in pediatric age, with episodic and continuous forms, morphological variability and migraine-like symptoms. The rectangular shape found in some cases calls into question the current nosographic limits and suggests the need for a broader pathophysiological understanding. Here we also propose possible new criteria for the diagnosis of Nummular Headache.