Hi Hell's itch or Sunburn usually occurs anywhere between 24 - 72 hours of exposure after being in the Sun. People with fairer skin and less exposure to sun have more chances of getting a Sunburn. Treatment includes topical applications which prevent the itching sensations and moisturizes the area. Please visit a Dermatologist for further evaluation and ,management. In case of further doubts, please feel free to write back to me. Regards Dr Prashik Meshram