<s>[INST] My sister has what starts as a rash and grows in what looks like a wart. It hurts, bleeds, falls off. Starts and spreads all over. She went to 2 doctors so far, no answers. She had multiple biopsies, nothing. It has spread over her back front arms and now legs. No clue...I am going with her to another dermatologist. I need to have an arsnel of questions. A allergist wouldn t do a thing because she was so enflamed from neck to buttocks. She colors and perms her hair often, she re entry traveled to Mexico (Thanksgiving) and it started late November early December. By Christmas she had the biopsy done. Any thoughts? [/INST] Hello, This itching rash can be due to two reasons 1 Some people develop allergies for the metals used in hip prosthesis. . You haven't mentioned what type of prosthesis was used. But it is one possibility. 2 Other possibility is Chat Doctor.  You haunt mentioned prior allergies. Allergy agent is different from one person to the her. You can't have allergy for celecoxib just because your neighbor is allergic.3 herpes zoster at a dermatome level. Reactivation of varicella zoster virus But after your doctor with </s>