My sister has recently got a red rash on her face (nose & cheeks) ,which was peeling and itching after some days a rash occurred on her back neck also when we consulted the doc she said that it's a sunburn. She prescribed a steroid cream and the face rash has disappeared a bit and the  back rash is healing. She asked her to get ANA and some other tests done. Both the tests were negative and normal. Is there anything that i should worry about ?