Hi;
This is a disease called as vasculitis; that primarily occur due to underlying autoimmunity affecting small blood vessels. These blood vessels get swollen and cause this red raised lesions on thighs. This can occur anywhere in the body. If it is restricted only to skin , and not in any other major organs like
kidney or lung then usually it’s good prognosis comparatively as it is in this case. She needs a course of steroids and immunotherapy. Duration of treatment shall be decided after seeing the patient.