Comorbid Conditions of Ehlers–Danlos Syndromes and Vulvodynia: A Latent Class Analysis

PURPOSE: Having an Ehlers-Danlos syndrome (EDS) or hypermobility spectrum disorder (HSD) may increase the likelihood of vulvodynia six-fold. Studying vulvodynia in EDS/HSD may help identify causes of vulvodynia and potential treatments. Currently there are no consistently effective treatment methods for vulvodynia. We aim to identify comorbid condition patterns and how they affect a participant's likelihood of screening positive for vulvodynia. DESIGN: Online survey. METHODS: A secondary analysis was conducted using latent class analysis on data from females aged ≥18 years with EDS or HSD (N = 1,016) who were screened for vulvodynia. RESULTS: Five comorbid condition patterns of 9 indicators were identified. Among the patterns 2 overarching comorbid condition phenotypes were present, 1) non-musculoskeletal phenotype (n = 185) comprised of mast cell activation disorder, gastrointestinal conditions, and dysautonomia; and 2) pain phenotype (n = 442) comprised of chronic pain and pelvic instability; 201 participants endorsed both phenotypes. The non-musculoskeletal phenotype incurred the smallest likelihood of screening positive, followed by the pain phenotype. Endorsed both phenotypes resulted in significantly greater likelihood of screening vulvodynia positive (p < 0.05) compared to one phenotype. CONCLUSIONS: Phenotypes may constitute 1) different pathways for developing vulvodynia and/or 2) different subtypes of vulvodynia and/or EDS. We hypothesize that as a person accumulates comorbid conditions, their allostatic load increases, and once a personal allostatic load threshold is crossed, vulvodynia may develop. CLINICAL IMPLICATIONS: Different pathways for developing vulvodynia may explain why there is no consistently effective treatment for vulvodynia. Phenotypes may be able to be used to develop personalized treatment methods.