Aziderm 20% is for external use only. You should always use it exactly as your doctor has told you. The affected area should be clean and dry before application. You must wash your hands thoroughly before and after applying this medicine. This medicine should be used regularly to get the most benefit from it. Do not use more than you need as it will not clear your condition faster and some side effects may be increased. If your condition goes on for longer than four weeks or gets worse at any time, let your doctor know. You can help this medicine work better by keeping the affected areas clean.