Introduction
Mixed vaginitis is caused by the simultaneous presence of at least two vaginal pathogens, contributing to an abnormal vaginal milieu and leading to the development of vaginal symptoms and signs(1). Nevertheless, simply identifying the presence of at least two vaginal pathogens in situ does not establish a cause–effect relationship with clinical symptoms and signs. For example, in patients with simple vaginitis, “vulvar pruritis” and “thick curdy discharge” are more likely to be reported by women with vulvovaginal candidiasis (VVC), while “thin white discharge” and “odor” are more commonly reported in women with bacterial vaginitis (BV)(2). Individual signs and symptoms have only limited value in the recognition of vaginitis. “Abnormal vaginal discharge,” “dyspareunia,” and “vaginal soreness” can occur with any kind of vaginitis. In addition, the presentation of mixed vaginitis can be atypical. Both pathogens require specific therapies for complete eradication(3). Therefore, in its simplest form, mixed vaginitis refers to the simultaneous presence of two or more potential pathogens in the lower genital tract, regardless of the clinical significance of the individual pathogens.
Today, approximately 20 lower genital tract-related infections have been recognized, such infections are caused by bacteria, fungi, protozoa, mycoplasma, and viruses(4). The majority of infections in the female reproductive tract (FRT) occur in the vagina and cervix. Numerous microorganisms are often linked to cervical infection, leading to cervicitis, including herpes simplex virus-2 (HSV-2), Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Mycoplasma, and human papilloma virus (HPV)(5). The most common forms of vaginal infection include bacterial vaginosis (BV), trichomonas vaginalis (TV), vulvovaginal candidiasis (VVC), and aerobic vaginitis (AV). Mixed vaginitis in this review encompasses these 4 common types of vaginitis.
The signs and symptoms of mixed vaginitis are often atypical, diagnosis cannot always be established, treatment is complicated and the vaginal microbiota is more likely to be perturbed in contrast to single-type vaginitis. Moreover, mixed vaginitis can induce long-term symptoms with intermittent exacerbations, and recurrence after treatment is common, leading to repeat visits to physicians and higher healthcare costs. Therefore, the major goal of this review is to help improve clinicians’ understanding of mixed vaginitis and discuss the therapeutic standard to reduce the disease burden and prevent associated complications.