Trichomonas vaginalis is a flagellated protozoan that causes a com-mon, usually sexually transmitted vaginitis that is often called “trich.” About 5 million cases occur each year in the United States (U.S. Surgeon General’s Report, 2001). It may be trans-mitted by an asymptomatic carrier who harbors the organism in the urogenital tract (see Table 47-1). It may increase the risk of contracting HIV from an infected partner.
Clinical manifestations include a vaginal discharge that is thin (sometimes frothy), yellow to yellow-green, malodorous, and very irritating. An accompanying vulvitis may result, with vulvo-vaginal burning and itching. Diagnosis is made by microscopic detection of the pear-shaped, mobile, flagellate organisms. In-spection with a speculum often reveals vaginal and cervical ery-thema (redness) with multiple small petechiae (“strawberry spots”). pH testing of a trichomonal discharge will demonstrate a pH greater than 4.5.
The most effective treatment for trichomoniasis is metronidazole (Flagyl). Both partners receive a one-time loading dose or a smaller dose three times a day for 1 week. The one-time dose is more con-venient; consequently, compliance tends to be greater. The week-long treatment has occasionally been noted to be more effective. Some patients complain of an unpleasant but transient metallic taste when taking metronidazole. Nausea and vomiting, as well as a hot, flushed feeling, occur when this medication is taken with an alcoholic beverage (disulfiram-like reaction). In view of these side effects, the patient is strongly advised to abstain from alco-hol while taking the medication.
Metronidazole therapy is contraindicated in patients with some blood dyscrasias or central nervous system diseases, in the first trimester of pregnancy, and in women who are breastfeed-ing. It is not prescribed without examination.
After menopause, the vaginal mucosa becomes thinner and may atrophy. This condition can be complicated by infection from pyogenic bacteria, resulting in atrophic vaginitis (see Table 47-1). Leukorrhea (vaginal discharge) may cause itching and burning. Management is similar to that for bacterial vaginosis if bacteria are present. Estrogenic hormones, either taken orally or inserted into the vagina in a cream form, can also be effective in restoring the epithelium.