Adolescent, Vaginal Discharge, Trichomonas

Abnormal vaginal discharge and dysuria suggest the presence of coexisting infection of the genital tract (eg, vaginitis or cervicitis) and urethra (eg, urethritis) or vaginitis that has produced vulvar inflammation with resulting discomfort during urination (external dysuria). The etiology of the infection is determined best by performing a gynecologic examination that includes collection of vaginal secretions for microscopic examination and endocervical swabs for testing for infection with Chlamydia trachomatis and Neisseria gonorrhoeae. The presence of motile, flagellated organisms, as observed in the patient in the vignette, indicates infection with Trichomonas vaginalis.

T vaginalis is transmitted almost exclusively by sexual contact, although it can survive for as long as 45 min on toilet seats, washcloths, and clothing and in bath water, suggesting the possibility of nonsexual acquisition. Approximately 20% to 50% of infected women have symptoms, including yellow vaginal discharge, vulvar inflammation and pruritus, dysuria, and occasionally abdominal pain. Dysuria may result from coexisting urethral infection or from discomfort associated with the contact of urine with inflamed vulvae. On physical examination, the vulvae often appear erythematous and edematous, and the vagina is erythematous with a yellow or green, frothy discharge. Punctate cervical hemorrhages, referred to as "strawberry cervix" or "colpitis macularis," are highly specific for trichomoniasis but are observed only in a minority of infected patients. Although lower abdominal tenderness to palpation, possibly due to severe vaginitis or regional lymphadenopathy, has been reported in some women, the presence of this symptom should raise concern about coexisting pelvic inflammatory disease due to C trachomatis, N gonorrhoeae, or other organisms.

The diagnosis of trichomoniasis in women generally is confirmed by finding motile, flagellated organisms on microscopic examination of vaginal secretions. Although rapid and inexpensive, this method has a diagnostic sensitivity of only 50% to 70%. Culture methods improve sensitivity but are more expensive and not employed routinely in most clinical settings. 

The treatment for trichomoniasis is oral metronidazole 2 g as a single dose for the patient and her partner(s). This simultaneous treatment plan results in a 95% cure rate. For patients who do not respond to single-dose therapy, oral metronidazole may be prescribed at a dose of 500 mg bid for 7 days. Because of concerns about potential mutagenicity, it has been suggested that metronidazole not be used during pregnancy. Existing data suggest, however, that the mutagenic risk  associated with short-term, low-dose therapy is extremely low. In view of this, some experts, including the Centers for Disease Control and Prevention, state that pregnant women who have trichomoniasis may be treated with a single 2 g dose of metronidazole.

Oral azithromycin (1 g once) or doxycycline (100 mg bid for 7 days) may be used to treat uncomplicated chlamydial infection of the cervix. For women who have uncomplicated gonococcal cervical infection, oral cefixime (400 mg once) or ciprofloxacin (500 mg once) are effective. Although the patient in the vignette has trichomoniasis, appropriate diagnostic testing for other sexually transmitted infections (eg. chlamydia, gonorrhea, and syphilis) is warranted because she may beconcomitantly infected with other sexually transmitted pathogens. However, treatment for these pathogens is not indicated unless diagnostic testing shows evidence of infection.

Centers for Disease Control and Prevention. 1998 guidelines for the
treatment of sexually transmitted diseases. MMWR Morb Mortal Wkly Rep.
Emans SJ, Laufer MR, Goldstein DP. Trichomonal vaginitis. Pediatric
and Adolescent Gynecology. 4th ed. Philadelphia, Pa: Lippincott-Raven;
Krieger JN, Alderete JF. Trichomonas vaginalis and trichomoniasis. In:
Holmes KK, Sparling PF, Mardh PA, et al, eds. Sexually Transmitted
Diseases. 3rd ed. New York, NY: McGraw-Hill; 1999:587-604
Lappa S, Moscicki AB. The pediatrician and the sexually active
adolescent. A primer for sexually transmitted diseases. Pediatr Clin
North Am. 1997;44:1405-1445