Hi, Thanks for writing to us. There could be many causes for such lesions like fungal infection (candidal balanoposthitis), lichen planus, irritant dermatitis, and etc. Candidal BP is the most common cause amongst all. So right now, I would advise you that, wash the area with lukewarm water twice in a day and apply candid B cream two times in a day.
To reduce the itchy, take oral cetrizine and avoid using soap over the affected area. Also take tablet fluconazole 150mg once in a week for two weeks. If the lesion does not resolve in two weeks, either consult a dermatologist online with a photo of the lesion or meet a qualified dermatologist in your area for diagnosis based treatment.