What is the differential diagnosis for a formerly active and healthy 70-year-old woman with worsening proximal weakness, torticollis, and a widespread raised red rash across her cheeks bilaterally?

Medically reviewed by Katlein Franca, MD Key Takeaways A pimply rash on the buttocks can be caused by irritants like tight clothes or bicycle riding.Home remedies like a cool compress or oatmeal bath ...

Medically reviewed by William Truswell, MD You may get a butt rash from skin infections, allergic reactions, or a condition ...