Repeated challenge with the hapten oxazolone provokes persistent vulvar mechanical sensitivity and labiar T cell changes in previously sensitized ND4 mice (HYP7P.258)

Epidemiological evidence suggests a link between environmental allergies and the risk of developing vulvodynia—a chronic provoked vulvar pain condition affecting up to 8-16% of 18-60 year old women. We have previously shown 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 final allergen exposure. T cell amplification in the draining iliac lymph nodes resolves within 5 days after final challenge. Persistent sensitivity in the skin is accompanied by sustained changes in skin T cells; CD44+ CD8 and CD4 subsets remain elevated, T cell transcription factors T-bet and FoxP3 continue to be upregulated for up to 17 days after 10 allergen challenges. This is the first characterization of immune infiltrate accompanying sustained allergen-provoked mechanical sensitivity that persists after the resolution of overt inflammatory events following repeated allergen exposures. Our findings can be used to used to elucidate the underlying etiology of allergy-driven subsets of chronic pain conditions.