The Emotional Allodynia Questionnaire: Preliminary Validation and Clinical Phenotyping in Fibromyalgia

Background: Despite IASP’s recognition of pain as a sensory and emotional experience, current assessment tools largely overlook affective hypersensitivity to socially neutral stimuli, a phenomenon we term “emotional allodynia” that appears particularly recurrent in fibromyalgia. Methods: This preliminary psychometric validation study evaluated the Emotional Allodynia Questionnaire (AEQ), an 11-item 0– 4 Likert scale designed to quantify maladaptive emotional responses to subtle relational stimuli (perceived unresponsiveness, loss of reciprocity) in 107 patients with fibromyalgia from a tertiary pain clinic (90.7% female, mean age 56.8 years, median VAS 8.0). Results: AEQ demonstrated excellent internal consistency (Cronbach’s α = 0.917, 95% CI: 0.880– 0.943). Exploratory factor analysis supported unidimensional structure (Kaiser–Meyer–Olkin, KMO = 0.90, loadings 0.55– 0.86). Confirmatory factor analysis provided partial support (CFI = 0.924, RMSEA = 0.104). Convergent validity showed moderate-to-strong Spearman correlations with Central Sensitization Inventory (CSI) ( ρ = 0.40), Pain Catastrophizing Scale (PCS) ( ρ = 0.57), Difficulties in Emotion Regulation Scale (DERS) ( ρ = 0.59), Beck Depression Inventory-II (BDI-II) ( ρ = 0.52), State-Trait Anxiety Inventory (STAI-Y) ( ρ = 0.51– 0.56, all p < 0.001). Principal Component Analysis revealed that AEQ loaded strongly on a shared affective-sensitization dimension (65.9% variance). Exploratory median-split AEQ-CSI phenotyping identified four distinct profiles - resilient, emotional allodynia, central sensitization, mixed - that differed across all measures (Kruskal–Wallis p < 0.001). Conclusion: These preliminary findings suggest that the AEQ may represent a promising and theoretically coherent instrument for assessing a relational-affective dimension relevant to nociplastic pain, warranting replication in larger, independent samples. Keywords: fibromyalgia, chronic pain, nociplastic pain, central sensitization, emotion regulation, psychometrics