Epidemiology of M35.4
Data on prevalence, patient demographics, and clinical course of eosinophilic fasciitis based on published case series.
~300 Cases in the literature
1 : 1 Male-to-female ratio
44.5 Mean age at onset (years)
Who it affects
Eosinophilic fasciitis can begin at almost any age, but it clusters in middle life and shows no strong gender preference. These figures are pooled from published case reports and single-centre cohorts.
30–60 Typical onset window most cases · fifth–sixth decade
1–88 Age range reported from paediatric to elderly onset
1 : 1 Gender distribution near-equal across pooled reports
13% With another autoimmune disease comorbidity in pooled patients
Clinical & laboratory frequency
How often each finding appears, pooled from a 2025 systematic review of 597 published patients. Skin induration that spares the fingers, with blood eosinophilia, is the recurring signature.
Triggers, course & response
A bout of unusually strenuous physical effort often precedes onset. Most patients respond to treatment, but a substantial minority relapse and combination therapy outperforms steroids alone.
30–50% Preceded by strenuous exertion reported before symptom onset
82% Respond to treatment overall any clinical improvement
56% Respond to corticosteroids alone monotherapy response
~25% Relapse after responding among initial responders