What are the characteristic skin findings in anogenital warts (human papillomavirus, HPV)?

From the Guidelines

Anogenital warts typically present as soft, flesh-colored or hyperpigmented papules or plaques in the genital and perianal regions, ranging from 1mm to several centimeters in size, and are usually asymptomatic but may cause itching, burning, or bleeding. These lesions can be flat, dome-shaped, or cauliflower-like (condyloma acuminata) and may appear as single lesions or in clusters, typically found on the penis, vulva, vagina, cervix, perineum, perianal area, and occasionally within the urethra, rectum, or oral cavity 1. The warts are caused by human papillomavirus (HPV), most commonly types 6 and 11, which are transmitted through direct skin-to-skin contact during sexual activity. According to the 2015 Centers for Disease Control and Prevention sexually transmitted diseases treatment guidelines, most sexually active persons will have detectable HPV at least once in their lifetime, and HPV is transmitted frequently between partners 1.

Some key characteristics of anogenital warts include:

• They can be painful, friable, and pruritic, although they are commonly asymptomatic 1
• In moist areas, they tend to be softer and more friable, while on dry skin they appear firmer and more keratinized
• They can cause itching, burning, or bleeding, especially when irritated by friction
• Application of 5% acetic acid (vinegar) may cause the warts to turn white (acetowhitening), though this finding is not specific to HPV infection and should be interpreted cautiously.

It's essential to use good lighting and magnification when examining patients, as some lesions may be subtle, and to consider the patient's sexual history and risk factors for HPV transmission 1.

From the FDA Drug Label

The incidence and severity of local skin reactions during controlled clinical trials are shown in the following table ns in the Treatment Area as Assessed by the Investigator (External Genital Warts) Imiquimod Cream Vehicle Females n=114 Males n=156 Females n=99 Males n=157 All Grades* Severe All Grades* Severe All Grades* Severe All Grades* Severe Erythema 74(65%) 4 (4%) 90(58%) 6(4%) 21(21%) 0(0%) 34(22%) 0(0%) Erosion 35(31%) 1 (1%) 47(30%) 2(1%) 8(8%) 0(0%) 10(6%) 0(0%) Excoriation/ Flaking 21(18%) 0(0%) 40(26%) 1(1%) 8(8%) 0(0%) 12(8%) 0(0%) Edema 20(18%) 1(1%) 19(12%) 0(0%) 5(5%) 0(0%) 1(1%) 0(0%) Scabbing 4(4%) 0(0%) 20(13%) 0(0%) 0(0%) 0(0%) 4(3%) 0(0%) Induration 6(5%) 0(0%) 11(7%) 0(0%) 2(2%) 0(0%) 3(2%) 0(0%) Ulceration 9(8%) 3(3%) 7(4%) 0(0%) 1(1%) 0(0%) 1(1%) 0(0%) Vesicles 3(3%) 0(0%) 3(2%) 0(0%) 0(0%) 0(0%) 0(0%) 0(0%) *Mild, Moderate, or Severe

The skin findings in anogenital warts include:

• Erythema (65% of females, 58% of males)
• Erosion (31% of females, 30% of males)
• Excoriation/Flaking (18% of females, 26% of males)
• Edema (18% of females, 12% of males)
• Scabbing (4% of females, 13% of males)
• Induration (5% of females, 7% of males)
• Ulceration (8% of females, 4% of males)
• Vesicles (3% of females, 2% of males) 2

From the Research

Skin Findings in Anogenital Warts

• Anogenital warts can manifest as small, flat-topped papules to large, cauliflower-like lesions on the anogenital mucosa and surrounding skin 3.
• The main manifestations of anogenital warts include cauliflower-like condylomata acuminata, keratotic and smooth papular warts, and subclinical "flat" warts 4.
• Warts can vary in appearance, with some being flat and others being raised, and can occur on moist or dry surfaces 4.

Types of Anogenital Warts

• Cauliflower-like condylomata acuminata are the most common type of anogenital wart and usually involve moist surfaces 4.
• Keratotic and smooth papular warts usually occur on dry surfaces 4.
• Subclinical "flat" warts can be found on any mucosal or cutaneous surface and are often only detectable through the presence of HPV DNA 4.

Diagnosis and Treatment

• Diagnosis of anogenital warts is typically clinical, but atypical lesions should be confirmed by histology 3.
• Treatment options for anogenital warts include patient-applied treatments such as topical imiquimod, podofilox, and sinecatechins, as well as clinician-applied treatments like podophyllin, bichloroacetic acid, and trichloroacetic acid 3.
• Surgical treatments, including excision, cryotherapy, and electrosurgery, are also available 3.