What commonly applied topical agent can cause a sunburn-like reaction?

5-fluorouracil is a commonly applied topical agent that can lead to a sunburn-like reaction due to its mechanism of action and effects on the skin. As a chemotherapeutic agent used primarily for the treatment of certain skin cancers and pre-cancerous conditions, 5-fluorouracil works by interfering with DNA synthesis in rapidly dividing cells, like cancer cells. However, in the process, it can also affect normal skin cells.

This interaction with healthy skin cells can result in skin irritation, redness, and inflammation, which is reminiscent of a sunburn. Patients may notice peeling, flaking, or blistering, all of which can arise as part of the inflammatory response triggered by the drug as it acts on both abnormal and normal cells. This characteristic reaction is a key consideration in the safe use of 5-fluorouracil, as it indicates that the drug is working, but it also serves as a warning that careful monitoring and management of skin side effects are essential during treatment.

While other topical agents listed can cause skin reactions, they typically do not lead to a sunburn-like appearance or are associated with different side effects specific to their pharmacological profiles.