Repeated oxazolone exposure provokes persistent vulvar mechanical sensitivity and labiar T cell accumulation in previously sensitized ND4 mice
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 mice. Here, we show that repeated oxazolone exposure produces persistent vulvar mechanical sensitivity in sensitized mice for 17 days after final allergen exposure. T cell amplification in the draining iliac lymph nodes and upregulation of inflammatory cytokine transcripts Ifn-_, Il-1_, and Cxcl2 resolve within 5 days after final exposure. However, increases in levels of skin-resident memory T cells persist through 21 days after 10 oxazolone exposures. T cell transcription factors T-bet and Foxp3 in the labiar skin also remain elevated in oxazolone exposed mice through 21 days post final exposure. This is the first evidence of sustained vulvar pain persisting after the resolution of overt inflammatory events following an allergic response, and can be used to elucidate the underlying etiology of subsets of vulvar pain.