Genital Skin Lesions

Skin lesions in the genital area are common, and the etiology can range from simple irritation to sexually transmitted diseases to malignancy. The appearance of the lesion, the presence of pain and/or itching, and a description of how the lesion has changed over time can help narrow the differential diagnosis. Be careful not to miss the characteristic chancre of syphilis, which will be a painless ulceration that resolves spontaneously, but may infect others and lead to the serious consequences of secondary or tertiary syphilis.

Differential Diagnosis

• Herpes simplex virus (HSV-1 and HSV-2) is the most common cause of genital lesions in the U.S.
  –Presents with prodromal tingling and genital discomfort before lesions
  –Lesions are always painful and appear as grouped vesicles on an erythematous base
• Condyloma acuminatum (“warts,” HPV)
  –Etiologic agent is human papilloma virus
  –Lesions usually painless and pearly with a smooth surface but may be filiform, fungating, and lobulated

• Molluscum contagiosum
  –Multiple, very small, painless, flesh-colored nodules with umbilicated centers

• Chancroid
  –Etiologic agent is Haemophilus ducreyi
  –Painful, solitary, and erythematous lesions
  –May present with dyspareunia and/or dysuria

Workup and Diagnosis

• History and physical examination including a sexual history and a complete skin exam
  –Separate lesions into painless and painful categories; however, note that an initially painless lesion may become painful following a secondary infection
• Viral culture is gold standard for HSV detection
• Tzanck test may be used to detect HSV and will reveal multinucleated giant cells and intranuclear inclusions
• RPR or VDRL serum tests screen for syphilis, but become positive only 6–8 weeks after primary infection
  –These tests have high false-positive rates
  –Serum FTA is more specific for syphilis
  –Early diagnosis of primary disease requires dark-field microscopic evaluation of infected tissue or IgM assay
  • Culture or Gram stain to detect chancroid
  • Condyloma accuminata can be diagnosed by applying acetic acid to lesions, which will turn acetowhite
  • Molluscum contagiosum is diagnosed by appearance
  • Wood's lamp may be used to detect erythrasma
  • Shave biopsy is diagnostic for psoriasis, Zoon's, and neoplasms
  • Lesions in older patients that are changing in size, appearance, or texture should always be biopsied to rule out carcinoma
  • All patients with a suspected STD require a full workup for HIV, syphilis, hepatitis B and C, and pregnancy

  Treatment

  • Herpes simplex virus: Antivirals (e.g., acyclovir) are best given within 24 hours of outbreak to reduce severity and duration of disease; acetaminophen, NSAIDs, and cool baths for symptomatic relief
  • Condyloma accuminata: Destruction of lesions with podophyllin, cryotherapy, cantherone, trichloroacetic acid, or laser can ablate lesions; topical immunotherapy with imiquimod or squaric acid is also successful
  • Tinea cruris: Topical (e.g., terbinafine) or oral antifungals (e.g., terbinafine, fluconazole)
  • Syphilis: Antibiotics (e.g., penicillin)
  • Molluscum contagiosum: Cryotherapy for mild disease; surgical removal for moderate disease
  • Chancroid: Antibiotics (e.g., azithromycin)
  • Low-potency topical steroids are necessary to treat psoriasis, Zoon's balanitis, and seborrheic dermatitis
  • If a red or white plaque persists despite topical therapy, biopsy the lesion to rule out carcinoma

Book Source Details

• Book Title: In a Page: Signs and Symptoms
• Author(s): Scott Kahan, Ellen G. Smith
• Year of Publication: 2004
• Copyright Details: In a Page: Signs and Symptoms, Copyright © 2004 Lippincott Williams & Wilkins.

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More About This Book: Title: In a Page: Signs and Symptoms Authors: Scott Kahan, Ellen G. Smith Publisher: Lippincott Williams & Wilkins Copyright: 2004 ISBN: 1-4051-0368-X