Clinical features of external genital warts.

External genital warts (EGWs) are a common sexually transmitted infection caused by the human papillomavirus (HPV). Although over 100 HPV types have been identified, some of which are associated with cancer, EGWs are caused by noncancerous HPV subtypes 6 and 11. This cutaneous manifestation of HPV infection can be asymptomatic or produce warty lesions that may assume a cauliflower-like, flat, papular, or keratotic appearance. Physical symptoms may also accompany warts, such as pruritus, burning, pain, and obstruction. EGWs typically appear in anogenital areas, such as the vulva, penis, groin, perineum, perianal skin, or mucosal surfaces. EGWs are typically a transient type of infection that often spontaneously regresses without treatment, but long-term remission rates are currently unknown. Treatment is determined according to the size and number of lesions, which can cluster or develop at multiple sites. Because of the individual variability in disease, treatment should be determined on a case-by-case basis. Further investigation, such as a biopsy, may be advisable in cases of atypical lesions, lesions that are unresponsive to therapies, and immunocompromised individuals, who are essentially more susceptible to HPV infections and less responsive to treatment. Although HPV testing is available, it is not currently recommended for detection and HPV typing. Differential diagnoses may include normal skin variations, other infectious or inflammatory diseases, and cancerous growths.