Pain is common after sexual assault (SA), but etiology of pain symptoms after SA is unknown. Preclinical studies suggest that the release of endogenous opioids during stress produces delayed-onset hyperalgesia. In human studies, individuals with >= 1 G allele at the mu-opioid receptor functional single nucleotide polymorphism A118G have been shown to have a reduced response to opioids. We hypothesized that if opioid-mediated hyperalgesia contributes to pain after SA, women SA survivors with 1 or more G alleles at A118G would experience reduced postassault pain. Among 52 European American women SA survivors presenting for care within 48 hours of SA, those with a G allele (12/52,23%) experienced less severe pain (F[1,39] = 11.55, P = .002) and a reduced extent of pain (F[1,41] = 11.01, P = .002) during the 6 weeks after SA. These associations between the presence of 1 or more G alleles and reduced pain severity and reduced pain extent after SA remained significant in multivariable models controlling for age, income, education, reported pain prior to assault, and pain at the time of initial evaluation.Perspective: These results suggest that endogenous opioid-mediated hyperalgesia may contribute to pain symptoms after sexual assault. Further studies examining mechanisms mediating the development of pain after sexual assault, and the potential influence of opioid-mediated hyperalgesia, are needed. (C) 2013 by the American Pain Society

Individual vulnerability factors influencing the function of the hypothalamic-pituitary-adrenal axis may contribute to the risk of the development of persistent musculoskeletal pain after traumatic stress exposure. The objective of the study was to evaluate the association between polymorphisms in the gene encoding FK506 binding protein 51, FKBP5, a glucocorticoid receptor co-chaperone, and musculoskeletal pain severity 6 weeks after 2 common trauma exposures. The study included data from 2 prospective emergency department-based cohorts: a discovery cohort (n = 949) of European Americans experiencing motor vehicle collision and a replication cohort of adult European American women experiencing sexual assault (n = 53). DNA was collected from trauma survivors at the time of initial assessment. Overall pain and neck pain 6 weeks after trauma exposure were assessed using a 0-10 numeric rating scale. After adjustment for multiple comparisons, 6 FKBP5 polymorphisms showed significant association (minimum P < 0.0001) with both overall and neck pain in the discovery cohort. The association of rs3800373, rs9380526, rs9394314, rs2817032, and rs2817040 with neck pain and/or overall pain 6 weeks after trauma was replicated in the sexual assault cohort, showing the same direction of the effect in each case. The results of this study indicate that genetic variants in FKBP5 influence the severity of musculoskeletal pain symptoms experienced during the weeks after motor vehicle collision and sexual assault. These results suggest that glucocorticoid pathways influence the development of persistent posttraumatic pain, and that such pathways may be a target of pharmacologic interventions aimed at improving recovery after trauma. (C) 2013 International Association for the Study of Pain. Published by Elsevier B. V. All rights reserved.

Sexual assault (SA) is common, but the epidemiology of acute pain after SA has not previously been reported. We evaluated the severity and distribution of pain symptoms in the early aftermath of SA among women receiving Sexual Assault Nurse Examiner (SANE) care, and the treatment of pain by SANE nurses. Severe pain (>= 7 on a 0-10 numeric rating scale) was reported by 53/83 women sexual assault survivors (64% [95% CI, 53-74%]) at the time of SANE evaluation and 43/83 women (52% [95% CI, 41-63%]) 1 week later. Pain in 4 or more body regions was reported by 44/83 women (53% [95% CI, 42-64%]) at the time of initial evaluation and 49/83 women (59% [95% CI, 48-70%]) at 1 week follow-up. Among survivors with severe pain at the time of initial postassault evaluation, only 7/53(13% [95% CI, 6-26%]) received any pain medication at the time of initial SANE treatment. These findings suggest that pain is common in SA survivors in the early postassault period, but rarely treated.Perspective: Acute pain is common after sexual assault. Practice guidelines for SANE nurses and others who provide care to sexual assault survivors in the early aftermath of assault should include specific recommendations for pain evaluation and treatment. Prospective longitudinal studies of pain outcomes among sexual assault survivors are needed. (C) 2012 by the American Pain Society. Published by Elsevier Inc. All rights reserved