Beyond Pain Intensity: A Patient-Informed Framework for Documenting Burden in Small Fiber Neuropathy

Small fiber neuropathy (SFN) is a sensory-autonomic neuropathy of thinly myelinated Aδ and unmyelinated C fibers that can produce neuropathic pain and multisystem autonomic symptoms. Although diagnostic criteria and confirmatory testing have improved recognition, SFN burden may remain underrecognized even after diagnosis. This narrative review identifies two complementary documentation failures. The translation problem arises when symptom labels and intensity ratings do not capture effects on sustainable function, cognitive workload, emotional well-being, and participation. The fragmentation problem arises when specialties assess multisystem symptoms without preserving their temporal pattern, co-occurrence, shared triggers, treatment trade-offs, and recovery costs. Reverse availability bias is proposed as a conceptual mechanism that may intensify both failures: symptoms or mechanisms not represented in clinicians' mental models may be overlooked in consideration and documentation. The review proposes an SFN Burden Integration Framework (SFN-BIF) that separates symptom presence, burden, and causal attribution and combines validated measures with six core documentation fields: temporal pattern, triggers and relievers, co-occurrence, recovery cost, functional consequences, and cognitive-emotional consequences. Longitudinal patient-reported information is integrated with neurological examination, skin biopsy, quantitative sensory testing, autonomic or organ-specific testing, and cognitive or functional assessment when indicated. Better integration may inform diagnosis and referral, treatment selection and trade-offs, rehabilitation and psychological care, disability assessment, phenotyping, and clinical trial outcome selection while preserving diagnostic rigor. The framework remains conceptual and requires prospective evaluation of validity, feasibility, clinical utility, and administrative burden.