A 23-year-old woman comes to the office due to 3 days of fever and dysuria. The patient also has had a pruritic, erythematous vulvar rash that is particularly painful during urination. She is sexually active with one partner, and they use condoms inconsistently. Temperature is 38.7 C (101.7 F), blood pressure is 120/80 mm Hg, and pulse is 84/min. There is suprapubic fullness on abdominal examination. Pelvic examination shows multiple tender, ulcerated lesions on the inside of the left labia minora. Speculum examination shows no cervical friability or mucopurulent discharge. The left inguinal lymph nodes are enlarged and tender. Urethral catheterization is performed due to difficulty with spontaneous voiding. Urinalysis results are as follows:
| Leukocyte esterase | positive |
| Nitrites | negative |
| Bacteria | none |
| White blood cells | 15/hpf |
Urine pregnancy test is negative. Which of the following tests would most likely establish this patient's diagnosis?
Infectious genital ulcers | ||
Painful | Herpes simplex virus |
|
Haemophilus ducreyi (chancroid) |
| |
Painless | Treponema pallidum (syphilis) |
|
Chlamydia trachomatis serovars L1-L3 (lymphogranuloma venereum) |
| |
This patient's multiple, painful genital ulcers are consistent with a genital herpes simplex virus (HSV) infection. Patients with a primary infection often have systemic symptoms (eg, fever) and develop a tender inguinal lymphadenopathy. HSV evolves from vesicles to open ulcers; patients with ulcers often have associated dysuria and sterile pyuria (eg, white blood cells [WBCs] but no bacteria on urinalysis) due to urethral and vulvar inflammation and passage of urine over the open lesion. In addition, some patients may develop acute urinary retention (eg, suprapubic fullness) due to either reluctance to urinate or from a lumbosacral neuropathy that can complicate the infection.
The appearance of genital HSV lesions can vary and mimic other disease processes as the lesions change from vesicles to ulcers. Therefore, a suspected clinical diagnosis of genital HSV requires laboratory confirmation via viral culture or PCR testing. Viral culture is most effective in patients with active HSV lesions (such as this patient) but has decreasing sensitivity as lesions heal.
(Choice A) Haemophilus ducreyi causes chancroid, a rare sexually transmitted infection that causes a painful genital ulcer and tender inguinal lymphadenopathy (less common in women). However, chancroid usually causes a papule that evolves into an large (1-2cm) ulcer with a gray/yellow exudate and a friable base. In addition, regional lymphadenopathy is often fluctuant and suppurative. Diagnosis is via bacterial culture; Gram stain typically show gram-negative rods.
(Choice B) KOH wet mount microscopy is used to diagnose vulvovaginal candidiasis, which can present with a pruritic, erythematous vulvar rash and dysuria; however, there are no associated genital ulcers.
(Choice C) Chlamydia trachomatis can cause dysuria and sterile pyuria (ie, WBCs but no bacteria) due to urethritis, but patients typically have concomitant acute cervicitis (eg, cervical friability, mucopurulent discharge). Lymphogranuloma venereum is caused by C trachomatis serovars L1-L3 and presents with small, painless ulcers followed by painful, suppurative inguinal lymphadenopathy (buboes).
(Choice D) Nontreponemal serologic testing (ie, rapid plasma reagin) is used for evaluation of syphilis; primary syphilis typically presents with a single painless ulcer (ie, chancre) and bilateral, nontender lymphadenopathy.
Educational objective:
Genital herpes simplex virus infection can present with painful, pruritic, vesicular or ulcerative lesions; dysuria; and inguinal lymphadenopathy. Clinical diagnosis requires confirmation with laboratory testing via a viral culture or PCR.