Brief Answer:
Contact dermatitis, wash with dermadew soap, calamine lotion, tablet ceterizine

Detailed Answer:
Hi
Welcome to HCM.
I have gone through your query.
It is difficult to diagnose a rash without examination, kindly upload the photos to provide you with specific advice. It might be contact dermatitis.
Presently I would suggest you not to scratch it, to avoid secondary infection. Wash the area with mild soap like dermadew. Apply calamine lotion with alovera to the affected area. I advice you to take over the counter antihistamine like ceterizine, which will reduce itching.

Also provide additional information, when did it start, have you come in contact with some substance that you usually won't.

Hope this helps.
Get back to us with photos, I'll be glad to help you out.
Take care.

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