Circumcised men were less likely to report penile coital injuries, with significantly decreased risk as early as 6 months after surgery. Thus, recent circumcision did not increase penile coital injury risk. Although coital injuries decreased over time in both arms, at 24 months, 31% of circumcised men and 42% of uncircumcised men still reported penile coital injuries in the past 6 months. As nearly all men who reported penile skin bleeding were a subset of those reporting soreness and abrasions/scratches/cuts, bleeding may reflect injury progression or a more severe manifestation, even if it did not merit medical attention.
Our study provides a needed counterweight to the literature describing penile injuries that usually require surgery. In an extensive literature review, we could identify only two comparable studies. A cross-sectional survey of general population men aged 18–67 in Mbale Town, Uganda, found a similarly high prevalence of self-reported penile coital injuries that did not differ by circumcision status: 15% soreness, 33% scratches or abrasions, 8% bleeding17
. Recent re-analysis of these data found a statistically significant association between STI history and any reported coital-injury in multivariable analysis, adjusted for condom use and number of sex partners [unpublished data; results available from authors]. In a cross-sectional survey of general population residents of Cape Town, South Africa, 21% of men and 16% of women reported coital bleeding in the past 3 months, although 75% was attributed to menses by participants18
. In multivariable analysis adjusting for number of sex partners and condom use, history of STI was associated with a 3.4 OR for recent coital bleeding18
. These cross-sectional studies are consistent with our prospective assessment. The frequent rate of these mild penile coital injuries could be of substantial importance because of potential associations with STI and HIV infection risk1–2, 18–19
The increased risk of gonorrhea found in our prospective analysis14
is unlikely to result directly from abrasions/scratches/cuts or bleeding of the penile skin. Nevertheless, penile coital injuries causing dermal compromise should be considered potential risks for HIV acquisition. There is a 2–4 fold increased risk of HIV infection among men and women with genital ulcer disease20–22
. Epithelial or mucosal barrier disruption enables increased HIV accessibility to target cells3–6
. We found a statistically and clinically significant increased risk of penile dermal injuries among uncircumcised men that may in part explain their increased HIV infection risk compared to circumcised men. Furthermore, the high frequency of coital injuries among uncircumcised men could place sex partners of HIV-positive uncircumcised men at greater risk of HIV acquisition.
While HSV-2 seropositivity and genital ulcers increased the likelihood self-reported penile injuries, injuries were still reported at 44% of visits by HSV-2 seronegative men and genital ulcers were present in only 2.5% of visits at which injuries were reported. Thus, ulcerative genital syndromes and HSV-2 did not explain most self-reported penile coital injuries.
It is possible that some reported penile coital injuries were symptoms of allergen or irritant dermatitis, resulting from the application of spermicides, lubricants, feminine hygiene deodorant sprays, industrial or other contact agents transferred by hand23
. Men who applied substances to their penises had increased risk of each type of penile coital injury. If penile coital injuries were, in part, explained by such mechanisms, then it is plausible that condom use and washing the penis soon after sex would be protective of “injury”.
Married men were less likely to report penile abrasions/scratches/cuts, while men with multiple recent sex partners had increased risk for each injury type. Marital status and number of sex partners may be proxies for frequency of sex or range of sexual practices. Frequent or vigorous intercourse and uncommon sexual positions are suggested risk factors for coital injuries24–26
. In this sample of young men, increasing age was associated with increased risk for reporting penile coital injuries, which might be associated with greater frequency of sex or a broader range of sexual practices. Reduced rates of reported penile coital injuries in both study arms over time might reflect regression to the mean, increased familiarity with the study questions, or another effect of repeated assessment. In general, though, genitourinary health measures improved over time in the cohort: the prevalence of STIs decreased14
, condom use increased, and reporting multiple sex partners decreased15
The disconnect between the recall period (past 6 months) and current examination may have limited the value of physical examination as a tool to verify penile coital injury reports. Self-reported injuries may represent misclassification of infectious or dermatologic syndromes, exacerbated or brought to the men’s attention following intercourse. We do not have physical examination data verifying the location, duration, or severity of reported injuries. Additional information regarding the characteristics of intercourse, sexual positions, specific events prior to or at the time of injury, and whether there were concomitant injuries in sex partners may prove useful for understanding the mechanisms of injury. Although not extensively or methodologically studied in women either, minor coital injuries from consensual vaginal intercourse are reportedly associated with hurried coitus25
, male-to-female genital disproportion5,24,26
, uncommon sexual positions24,25–26
, and vaginal astringents or “tightening” agents27
. Further study is needed to verify the nature and causes of coital injuries in both males and females to identify potential mechanisms for increased risk for STIs and HIV.
Circumcision, condom use and penile hygiene, provided protection against reported penile coital injuries. Coital injury risks included: increasing age, multiple recent sex partners, application of substances to the penis prior to sex, HSV-2 seropositivity and genital ulcers. The mechanisms by which circumcision confers protection against penile coital injuries remain unknown. The high frequency of penile coital injuries reported in our cohort supports the need to verify penile coital injuries, their correlates in female sex partners, and the mechanisms by which such injuries may increase risk for STIs and HIV infection.