Blister in the groin

Patient: Hi doctorI got a small blister with black head on it in my upper thigh. This was followed by 4 or 6 blisters in my groin area.i have attached photo of the same. All on the right side groin. Nothing in the left side and nothing on the penis. These blisters do not itch. These are curing a little and I could not see any scab. Can you please help me here…

Doctor: