Repeated challenge with the hapten oxazolone provokes persistent vulvar mechanical sensitivity, labiar mast cell accumulation and nerve overgrowth in previously sensitized ND4 mice (HUM1P.270)

Abstract

Vulvodynia is a chronic vulvar pain condition affecting up to 8-16% of 18-60 year-old women. Epidemiological studies have associated an increased risk of developing vulvodynia with a history of seasonal and insect allergies. We have previously demonstrated that acute labiar exposure to the hapten allergen oxazolone provokes increased vulvar mechanical sensitivity in ND4 Swiss mice. Here, we show that repeated oxazolone challenge produces persistent vulvar mechanical sensitivity in sensitized mice for at least12 days after 10 allergen exposures. This persistent sensitivity is accompanied by mast cell accumulation and overgrowth of cutaneous neurites both of which persist for at least 14 days after the final allergen exposure. These changes are accompanied by an early and transient increase in mRNAs encoding CADM1 - an adhesion molecule that facilitates nerve-mast cell synapses - in the skin and mRNAs encoding the inflammatory cytokine IL-6 in the spinal cord. Taken together, these neuroimmune biomarkers may serve as potential diagnostic/therapeutic targets for specific allergy-driven subsets of chronic vulvar pain.