I found this book to be very useful for the RCPSG Diploma in Dermatology exam. It has MCQs (using the single best answer format) covering much of the syllabus from the RCPSG. In addition there are very good explanations in the answers section for each topic.
an excellent revision guide - the first for this new examination. An essential buy for all aspiring dermatology consultants by an author who was inspired to write this from first hand experience and who passed the exam first time with outstanding results.
A useful aid in revision, especially as it summaries conditions into helpful lists and tables. The questions are quite straight forward and I am not sure if this is representative of the exam (not done yet). Worth reading.