A 56-year-old male presented with multiple skin-colored umbilicated papules on the pubic, penis, and scrotum without itch and pain (). The lesion first appeared as one skin-coloured papule on the scrotum for the past 2 years PTC. One and a half years later, the papules increased in number for more than 10 papules. Six months later, papules multiplied and spread over the scrotum, penis, and pubic. There has been a history of promiscuity with nine female prostitutes since 2 years ago and had sexual contact with the prostitute who has the same lesions. Physical examination of the pubic, scrotum, and the shaft of the penis showed some papules with central umbilication. A Tzanck smear with Giemsa staining showed Henderson–Paterson’s bodies (). While VDRL, TPHA, and HIV tests were nonreactive. The patient was treated with 20% KOH solution applied by the patient once daily for 4 weeks on the left side of the pubic, penis, and scrotum. The right side of the pubic, penis, and scrotum was treated with 80% TCA once a week, as for comparing the efficacy of MC treatment. The MC lesions on both sides gradually became smaller after 2 weeks of treatment and disappeared on day 31. The patient complained of pain and stinging sensation in 3–5 minutes after 20% KOH being used, and lesions became redness for 4–5 days. With 80% TCA solution, there were side effects such as pain and stinging sensation shortly after being used, which last about 10 seconds. Both treatments using 20% KOH and 80% TCA solutions caused side effects of hypopigmented macules.
A 24-year-old female presented with erythematous papules without itch and pain around the vulva. The lesions first appeared 3 weeks prior to consultation (PTC) as one erythematous papule on the vulva, then spread to the pubic area. She admitted having promiscuity, and mostly her partners did not use condoms. Physical examination on the pubic and vulva showed erythematous papules with umbilication at the central part (). Venereal disease research laboratory (VDRL), Treponema pallidum hemagglutination (TPHA), and human immunodeficiency virus (HIV) tests were nonreactive. The patient was treated with 20% KOH solution applied by the patient once daily before bedtime for 25 days. The patient felt a stinging sensation a short time after the first 5 minutes of the application. The MC lesions gradually subsided from day 17 after treatment, disappeared on day 25, and became post-inflammatory hyperpigmentation on day 51 of observation.