Treating Fatigue in Sarcoidosis—A Phenotype-Based, Treatable-Traits Approach

Fatigue is one of the most prevalent and debilitating symptoms in sarcoidosis, yet its mechanisms remain poorly defined and therapeutic responses are often unsatisfactory. Given its multifactorial nature and the limitations of uniform treatment strategies, there is a need for more structured and clinically actionable approaches. This narrative review summarizes current evidence on biological, behavioral, treatment-related and comorbidity-related contributors to sarcoidosis-associated fatigue and proposes an author-developed framework informed by the treatable-traits concept. Rather than defining mutually exclusive categories, the framework describes clinically recognizable fatigue patterns, including active inflammatory fatigue; treatment-related fatigue; comorbidity-related fatigue; sleep-related fatigue; neuropsychiatric, cognitive, pain and small-fiber neuropathy-related fatigue; deconditioning and lifestyle-related fatigue; and residual/post-sarcoidosis fatigue. The proposed approach emphasizes systematic identification and prioritization of one or more relevant treatable traits, followed by targeted intervention and reassessment. It is intended to support clinical reasoning rather than to serve as a validated classification. The framework integrates previously recognized contributors to fatigue into a structured clinical pathway and highlights areas in which direct evidence for fatigue-specific interventions remains limited. Prospective validation is required to determine its reproducibility, clinical utility and ability to identify patients who may benefit from trait-matched interventions.