Patients with indolent systemic mastocytosis (SM) experience significant limitations in their daily lives that directly correlate with symptom burden, according to a recently published study presented at the EAACI 2025 Congress.
What is indolent SM?
Indolent SM refers to a subtype of systemic mastocytosis that is typically slow-progressing and does not affect life expectancy. However, patients often experience a variety of symptoms, including flushing, diarrhea, and constipation, which can severely impact daily functioning and quality of life. Epidemiological studies indicate that indolent SM accounts for approximately 85% of all SM cases.
The study’s authors aimed to better understand the impact of indolent SM on daily activities through the Perceptions, Realities, and Insights on Systemic Mastocytosis (PRISM) survey.
The survey was administered to over 500 patients with indolent SM in Austria, France, Germany, Italy, Spain, Switzerland and the U.K. between 2022 and 2023. Over 65% of respondents had moderate to severe symptoms, based on the Total Symptom Score (TSS).
The questionnaire consisted of 119 items assessing the emotional, cognitive and mental health symptoms associated with indolent SM.
Researchers documented notable differences in daily life impact according to TSS scores. Over 60% of patients with a TSS over 28 (a score indicative of moderate-to-severe symptoms) reported significant limitations in physical activity, work and studies. In comparison, fewer than 45% of patients with a TSS score under 28 reported impacts in these areas.
Similarly, 56% of patients in the high TSS group reported sleep disturbances, 47% reported difficulties in relationships and 44% reported limitations in leisure activities — compared with 30%, 19% and 29%, respectively, in the low TSS group.
Read more about SM signs and symptoms
A significant number of patients reported feeling misunderstood by others regarding their disease, and nearly 30% said they felt that the disease was “controlling their life.” Additionally, 42% of patients with low TSS and 75% of those with high TSS reported experiencing anxiety or depression.
“These findings underscore the profound socio-emotional impact of ISM on patients, highlighting the need for a multidisciplinary approach that enhances overall quality of life and integrates mental health support into the broader disease management strategy,” the authors wrote.
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