the effect of fluorouracil may be to create a thymine deficiency which provokes unbalanced growth and death of the cell. Keratoses: Apply twice daily until erosion occurs (usually 2–4 wks).

A database search of PubMed and Embase was performed from 1965 to April 2012 using the terms 'actinic keratoses', 'solar keratoses', 'topical 5-fluorouracil', 'topical 5-FU', 'double-blind ...