Imiquimod (Aldara) 5% cream is the first of a new class of drugs called Immune Response Modifiers to become commercially available. It is currently approved as a treatment for external genital warts and approval is pending in a number of countries for the treatment of superficial BCC and actinic keratoses.

Its mode of action is via the stimulation of the patients own innate and cell-mediated immune systems through the activation of toll-like receptor 7 (a conserved microbial pattern recognition receptor). Thus it is the patients own locally activated immune system which destroys the BCC.

The ideal BCC for imiquimod therapy is a superficial BCC on and area of the body where post operative scarring, or delayed healing may be a problem. The treatment regime is once daily application of the cream to the BCC, 5–7 times a week for 6 weeks. Local skin reactions may be pronounced and necessitate “rest periods” during the 6 weeks treatment period.