trichomoniasis but is visible without colposcopy in only about 2% of infected patients Clinical Assessment For patients of all ages, Trichomonas vaginalis is best detected by antigen testing using vaginal swabs collected and evaluated by immunoassay or nucleic acid amplification test with a sensitivity of greater than 95% Historically, the diagnosis was made if characteristically motile, flagellated trichomonads are seen in a saline suspension of discharge examined microscopically within about 15 minutes after the specimen has been obtained ( Fig 92.1 ) However, the sensitivity rate for wet mount examinations is only 50% Cultures from a specialized parasite medium have a sensitivity of 85% to 95%, but results are delayed, generally taking several days Management Metronidazole is effective for the treatment of vaginal trichomoniasis The dosage for infants is 15 mg/kg/day orally in two to three divided doses for days Recommended treatment of adolescents includes metronidazole g orally in a single dose, 500 mg orally twice daily for days, or tinidazole g orally in a single dose Because trichomoniasis is a sexually transmitted disease, the patient’s partner(s) must also be treated (expedited partner therapy) or referred for treatment Nausea and an unpleasant taste are common side effects of nitroimidazoles Alcohol should be avoided during treatment and 24 to 72 hours after treatment to prevent the occurrence of more severe abdominal pain, vomiting, flushing, and headache (disulfiram reaction) Patients should continue to abstain from alcohol for 24 hours after completion of metronidazole and 72 hours after completion of tinidazole Recent data indicate that metronidazole is not a teratogen, but many clinicians prefer to postpone treatment of pregnant patients until the second trimester Intravaginal clotrimazole (two intravaginal tablets at bedtime for days) can provide symptomatic relief for pregnant patients but will cure only 10% to 20% SHIGELLA VAGINITIS Clinical Considerations Clinical Recognition Shigella flexneri, Shigella sonnei, Shigella boydii, and Shigella dysenteriae can produce vaginal infections in infants and children but not appear to cause genital disease after puberty The vaginitis is characterized by a white to yellow discharge that is bloody in three-fourths of cases Associated pruritus and dysuria are uncommon One-third of patients have diarrhea that precedes, accompanies, or follows the vaginal discharge On inspection, the vulvar mucosa is often inflamed or ulcerated Clinical Assessment The diagnosis is established by culture of a specimen of vaginal discharge Rectal cultures are positive for Shigella species in some cases Management Patients with Shigella vaginitis should be treated with oral antibiotics chosen on the basis of sensitivity testing If the antibiotic sensitivity is unknown, trimethoprim-sulfamethoxazole (8 mg/kg/day orally of trimethoprim in two divided doses for days) should be used STREPTOCOCCAL VAGINITIS Clinical Considerations Clinical Recognition S pyogenes can be identified in cultures of vaginal specimens taken from about 14% of prepubertal girls with scarlet fever Most of these vaginal infections produce either no symptoms or minor discomfort, but a few patients develop outright vaginitis with a purulent discharge Streptococcal vaginitis can accompany or follow symptomatic pharyngitis and causes genital pain or pruritus which can mimic candidal or gonococcal vaginitis Clinical Assessment A swab of the patient’s discharge should be cultured to verify the clinical diagnosis Testing for other potential etiologies, such as gonococcal infection, should be considered on a case-by-case basis Management As for any other infection with group A β-hemolytic streptococci, penicillin is the preferred antibiotic Intramuscular benzathine penicillin G is an alternative if poor compliance with oral treatment is anticipated For some patients who are allergic to penicillin, a 10-day course of a narrow-spectrum (first-generation) oral cephalosporin is indicated However, as many as 5% to 10% of penicillin-allergic people also are allergic to cephalosporins Patients with immediate or type I hypersensitivity to penicillin should not be treated with a cephalosporin; in these patients, oral clindamycin (20 mg/kg/day in three divided doses; maximum, 1.8 g/day) for 10 days is an acceptable alternative Additionally, an oral macrolide or azalide (such as erythromycin, clarithromycin, or azithromycin) is also acceptable for patients allergic to penicillin Therapy for 10 days is indicated except for azithromycin (12 mg/kg/day; maximum, 500 mg on day 1, then mg/kg/day; maximum, 250 mg/day), which is given on days through CANDIDAL VAGINITIS Clinical Considerations Clinical Recognition Candidal vaginitis is one of the most common causes of vaginitis in pubertal adolescents C albicans frequently colonizes the vagina after the onset of puberty when estrogen stimulates local increases in glycogen stores and acidity that both appear to enhance its growth If the ecologic balance of the vagina is changed by inhibition of the normal bacterial flora, impaired host immunity, or an increase in the availability of nutrients (broad-spectrum antibiotics, immunodeficiency states, corticosteroids, diabetes mellitus, pregnancy), the resulting proliferation of Candida may produce symptoms However, most patients with candidiasis have no identifiable predisposing risk factors Because of the importance of estrogen in promoting fungal growth, candidal vulvovaginitis is rare among prepubertal girls Clinical Assessment The most common clinical manifestation of vulvovaginal candidiasis is vulvar pruritus In severe infections, vulvar edema and erythema can occur “External” dysuria is produced when urine comes in contact with the inflamed vulva Vaginal discharge is variable in quantity and appearance In severe cases, the vaginal vault is red, dry, and has a whitish, watery, or curd-like discharge that may be relatively scanty Patients with mild disease may have only intermittent itching and an unimpressive discharge The diagnosis can be made with the presence of C albicans on wet mount, Gram stain, or culture of vaginal discharge in a patient with vaginitis symptoms; however, candidiasis is most often a clinical diagnosis—testing can be limited to patients who are not responding to appropriate therapy or if an alternative diagnosis is being considered Microscopic examination of a sample of vaginal discharge suspended in 10% potassium hydroxide solution to clear the field of cellular debris can provide a rapid diagnosis of candidiasis if hyphae are seen However, in as many as 50% of cases, wet mounts are falsely negative Therefore, although the presence of C albicans can be confirmed by laboratory tests, the diagnosis and subsequent treatment of this infection should be guided by the presence or absence of clinical disease It is important to remember that candidal vaginitis does not exclude sexually transmitted infections Management Topical imidazoles will promptly cure 80% to 90% of patients with candidal infections Most are available without prescription The creams are packaged with intravaginal applicators, but many premenarcheal and virginal girls can be treated adequately and more comfortably by applying cream to the vulva alone Effective, nonprescription, short-course treatments of patients with mild to moderate candidal vulvovaginitis include clotrimazole 2% cream (5 g intravaginally at bedtime for three nights), miconazole 200-mg suppositories (one suppository at bedtime for three nights), and tioconazole 6.5% ointment (one full applicator as a single dose) For patients with severe discomfort, one of the 5- or 7-day formulations of a topical agent is likely to be more effective Creams and suppositories in this regimen are oil-based and might weaken latex condoms and diaphragms Fluconazole, 150-mg oral tablet in a single dose, cures candidal vulvovaginitis as effectively as the topical preparations, and many patients prefer oral to topical treatment However, the risks, albeit low, of systemic toxicity and allergy are important disadvantages of oral antifungal agents BACTERIAL VAGINOSIS Clinical Considerations Clinical Recognition Bacterial vaginosis is a syndrome characterized clinically by the presence of three of the following four signs: (i) a homogeneous, white adherent vaginal discharge; (ii) vaginal pH above 4.5; (iii) a fishy, amine-like odor released when 10% potassium hydroxide solution is added to a sample of the discharge; and (iv) the presence of clue cells (Amsel criteria) The syndrome occurs when lactobacilli that normally predominate in the genital tract are displaced by an overgrowth of mixed flora, including Gardnerella vaginalis, Mobiluncus species, other anaerobes, and Mycoplasma hominis What accounts for this change in the