A 20-year-old woman comes to an urgent care center due to pain with intercourse and dysuria for the last 3 days. She also has had low-grade fevers and a mild headache. The patient is otherwise healthy and takes oral contraceptives only. She has no history of urinary tract or sexually transmitted infections. The patient is sexually active and recently began a relationship with a new partner. Temperature is 37.2 C (99 F). The abdomen is soft and nontender. Pelvic examination shows multiple, painful, shallow ulcers with an erythematous base on the left labium. No vaginal discharge is present. Bimanual examination reveals no cervical motion tenderness. There is bilateral tender inguinal lymphadenopathy. Which of the following is the best diagnostic test for this patient's condition?
Genital ulcer disease | ||||
Syphilis | Genital herpes | Chancroid | Granuloma inguinale (donovanosis) | |
Causative agent |
|
|
|
|
Description |
|
|
|
|
Lymphadenopathy |
|
|
|
|
Diagnostic tests |
|
|
|
|
RPR = rapid plasma reagin. | ||||
This patient most likely has a herpes simplex virus (HSV) infection. HSV classically presents with multiple, painful genital ulcers with a characteristic erythematous base, dysuria (likely due to irritation of the ulcers), tender bilateral lymphadenopathy (common with primary genital HSV infection), and systemic symptoms (eg, fever, headache) in the setting of a new sexual partner.
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 PCR, viral culture (low sensitivity, particularly as lesions heal), direct fluorescence antibody testing, or Tzanck smear (showing multinucleated giant cells).
(Choice A) Lymph node biopsy is a relatively invasive procedure typically used to exclude malignancy or certain infections such as tuberculosis. Biopsies of genital lesions may be performed if the diagnosis is unclear or if there is no response to initial treatment.
(Choice B) Darkfield microscopy can be used to diagnose syphilis, which typically presents with painless ulcerations (chancre) and bilateral, nonpainful lymphadenopathy.
(Choice C) Gonorrhea, caused by Neisseria gonorrhoeae, commonly results in urethritis, cervicitis, and pelvic inflammatory disease; Gram stain can reveal gram-negative diplococci. Chancroid (due to Haemophilus ducreyi) presents with purulent ulcers with ragged borders and suppurative lymphadenopathy; Gram stain may occasionally reveal gram-negative rods in a school-of-fish chain.
(Choice E) Potassium hydroxide is a strong base that destroys epithelial cells and leukocytes but not fungus. Therefore, KOH can clear a specimen of cellular debris so that fungal elements may be visualized under a microscope. KOH preparation is often used to diagnose vulvovaginal candidiasis, which typically presents with a white vaginal discharge; genital ulcers would be atypical.
Educational objective:
The finding of multiple painful genital ulcers and constitutional symptoms in a sexually active patient is highly suggestive of primary genital infection with herpes simplex virus. The diagnosis can be established by PCR testing, direct fluorescence antibody testing, or Tzanck smear.