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 26-year-old male presented with multiple skin-colored umbilicated papules on the penis, without itch and pain (). The lesions first appeared as one skin-colored papule on the penis shaft for the past 1 month PTC. Over time, 3 weeks after, the skin lesions were spread over the base of the penis and increase in number. There was a history of promiscuity with several female prostitutes. Physical examination on the shaft and the base of the penis revealed several papules with central umbilication. VDRL, TPHA, and HIV tests were nonreactive. The patient was treated with 20% KOH solution applied by the patient twice daily for the lesions. All of the MC lesions disappeared on day 20 of observation. The patient felt a stinging sensation after 3–5 minutes application of the 20% KOH solution. Furthermore, it also caused other side effects such as erosions and post-inflammatory hypopigmentation.