When should I call my doctor about a rash during immunotherapy?

If you have a severe, extensive, blistering, or painful rash and are receiving immunotherapy, call your doctor to get their advice. It's especially important to call about rashes that involve the eyes or a mucous membrane, such as your mouth, caused by immunotherapy.

This matters because some types of immunotherapy can cause a severe and sometimes extensive rash, and your skin may also become dry or blistered. Because these reactions can be more serious than the milder skin problems often seen with radiation therapy or chemotherapy, it's important to let your health care team know promptly so the rash can be treated.

The same idea applies to targeted therapy: if you develop a rash while on targeted therapy, talk with your doctor before stopping the treatment. More generally, the article advises telling your health care team about any skin changes so they can be treated promptly, and making note of all the problems your team asks you to call about. Your healthcare team is the best source for guidance about your specific treatment and symptoms.