Are you sure that what you have is angular cheilitis and not cold sores? That would be my first thought posed. If it is angular cheilitis, you most likely need some sort of antifungal medication, steroid, etc. If it's cold sores, you would need to go on Acyclovir (Zovirax). That being said,...
I believe Accutane can treat mild phyma, or prevent recurrence of phyma. For moderate to sever rhinophyma, the treatment of choice is laser. The does of Accutane you are on is high (60mg), and if your rhinophyma is worsening, I would consider laser. You do need a wash out period of 3-6 months...
Small gaps up to a month or little longer have no significant impact on the end results of the therapy as long the total dose of the treatment is eventually achieved. It is the total dose not the daily dose that seems to be the determining factor in achieving long lasting control of acne...