A person should consider seeing a dermatologist if they develop cysts, nodules, or deep, painful acne. These severe forms of acne often do not respond to over-the-counter treatments and can lead to permanent scarring if left untreated. Cysts and nodules are large, inflamed bumps that form deep within the skin and can be particularly painful. A dermatologist can provide specialized treatments, such as corticosteroid injections, prescription medications, or extraction procedures, to reduce inflammation and prevent long-term damage.