Diagnosis, management and the burden of symptoms of mastocytosis from the physician's perspective: A nationwide study.

Mastocytosis is categorized into cutaneous mastocytosis (CM), mast cell sarcoma and systemic mastocytosis (SM). Within SM, indolent SM (ISM) is the more frequent subtype. Adult patients with CM but without an extracutaneous biopsy are classified as having mastocytosis in the skin (MIS), a provisional diagnosis. Mastocytosis patients may experience a wide range of symptoms that significantly impact their quality of life (QoL). In France, the estimated prevalence of mastocytosis and the burden of symptoms remain unknown. To address this, we conducted a national online survey to estimate the number of mastocytosis diagnoses and assess the burden of symptoms from the physician's perspective. Overall, 1169 of the 6239 physicians solicited completed the survey. These physicians reported managing 4121 patients of whom only 53% had ISM. By contrast, CM and MIS were reported in more patients than expected at 17% and 25% respectively. The estimated prevalence of mastocytosis in France was 8.5 per 100,000, which is lower than recent epidemiological studies and is associated with significant regional variability (p < 0.001). Among patients with ISM or MIS, 53% experienced moderate to severe symptoms-mainly affecting the skin, digestive system and general health-which impacted most QoL domains assessed. These findings highlight the need to improve awareness, access to diagnostic workup for mastocytosis (especially for patients with MIS and CM) and enhance QoL for patients.