"Not listening to patient"

My mother in law had to go to radiology for a CT scan she told the staff that she was allergic to iodine so couldn’t use that, they didn’t listen and used iodine anyway and she has now came out with a full body rash that’s she now seeing a dermatologist doctor for as it’s so bad and has been prescribed several different creams, wash and antihistamines to counter act the rash on her body.

She is struggling to walk and sleeping is a joke as it’s keeping her up all night this could of been avoided if they listened to the patient