Subclinical human papilloma virus infection in condylomata acuminata patients attending a VD clinic.

In 37 (77%) of 48 patients with external genital warts, application of 5% acetic acid revealed areas of acetowhite epithelium. The lesions were not clinically apparent before acetic acid was applied but were easily detected without the use of a colposcope. In a control group of 20 patients with chlamydial urethritis and no history of genital warts, none had acetowhite genital lesions. Histological examination of biopsy specimens from the flat acetowhite lesions showed HPV infection with koilocytosis in 29 (78%) and in 3 (8%) intra-epithelial neoplasia grade II-III. Using in situ hybridization with commercially available biotinylated DNA probes, HPV types 16/18 could be detected in 7 (24%) patients with koilocytosis and in 3 (100%) patients with dysplasia. Simultaneous infection with HPV types 6/11, 16/18, and 31/33/35 was found in 8 of the 13 HPV DNA-positive patients. It is concluded that subclinical HPV-induced acetowhite lesions are common among patients with genital warts and that these flat lesions may be associated with a high grade of dysplasia. Consequently, routine use of the acetic acid test on the genital epithelium is recommended in patients with condylomata acuminata in order to diagnose and treat all HPV-infected areas.