Im on 40 MG of Isotretinoin. I have been on accutane and have tanned since August-now. I went tanning and forgot to put on SPF on my lips and got fever blisters/cold sores.They went away and I went back to tan and put SPF on my lips AND put the UVA/UVB protective winkies that you use on your eyes when you tan but I used them on my lips and now I seem them coming back again! Why? I also accidentally used Chapstick that I used when I had my cold sores, could this have been why they came back?