The presentation is non specific and could point towards an infection like scabies or an allergic reaction called urticaria. In both the cases, dettol is never prescribed - so kindly refrain from such practices. Meet a Dermatologist for better understanding of your current scenario and appropriate treatment approach. You can consider having OTC anti-allergic medications for symptom relief and applying calamine lotion on affected areas.

You might have acute idiopathic urticaria and if you're saying that you have a burning sensation while urination then you must've developed an urinary tract infection. A lot of the times infections are a common trigger for urticaria. I'm saying all of this based on your complaint. But to verify this you will still need to visit a dermatologist. There are many reasons (outside of urticaria) why you can get itchy rash(viral etc). Plus, you might need antibiotics which cannot be prescribed without examination. So visit a dermatologist near you.