The authors of the article referenced below looked at the use of topical fluorouracil and it’s affects on improving photoaging in skin. Topical fluorouracil (5FU) has become a standard treatment of actinic keratoses (AKs). For treatment of AKs it is applied to the skin once or twice daily for 2-4 weeks. It produces significant and predictable irritation and inflammation. When the skin is healed there is always a decrease in the number of AKs. A “side benefit” of the AK treatment in many patients was improved skin (smoother, more even color, and a decrease in fine wrinkles). This improvement appears to come from the wound-healing response of the skin.
The authors end the article with this observation:
Evidence is accumulating that even minimal epidermal injury, such as that from nonablative laser resurfacing, microdermabrasion, and now topical fluorouracil, can lead to mild to moderate clinical improvement. It is likely that other topical agents such as diclofenac gel or imiquimod that have similar skin-injuring properties in photodamaged skin may have a similar restorative effect.
Although the standard course of therapy may last only 2 to 3 weeks, the ensuing reaction can persist for several more weeks. That reaction looks like this (photo credit):
The cost of topical 5FU is much less than ablative laser resurfacing. It is also unlikely to achieve (at least consistently) the same degree of improvement. For treatment of AKs, it is a great treatment with the side benefit of improved skin.
Topical Fluorouracil for Actinic Keratoses and Photoaging: A Clinical and Molecular Analysis; Arch Dermatol. 2009;145(6):659-666; Dana L. Sachs, MD; Sewon Kang, MD; Craig Hammerberg, PhD; Yolanda Helfrich, MD; Darius Karimipour, MD; Jeffrey Orringer, MD; Timothy Johnson, MD; Ted A. Hamilton, MS; Gary Fisher, PhD; John J. Voorhees, MD