I too am in my fourth month of Isotretinoin. The derm upped my dose to 80mg per day, and the last two or three days I have gotten a very itchy rash all over my upper body. Benadryl helped some with the itchiness, but not with the rash itself. I know this does not help with your question, but am wondering what the dermatologist decided for your son. I thought mine were either hives or a type of eczema. I'm just not sure. It's small patches/whelps that have some tiny bumps/dry skin. I don't want to be taken off of it either, but I just know that this is intensely itchy. I don't think I can do this for another month and half like this.

The derm assured me that it had nothing to do with the Claravis (though I have my doubts). He put him on a course of steroids and daily Allegra and the hives cleared up quickly. He also used cortizone with moisturizers to control the itching. Just yesterday they came back, but not nearly as bad. It seems to coincide when he's exposed to allergens, mainly bug bites. I think the Claravis has his system so hyped up that a few bug bites during soccer practice sends his immune system into overdrive. He started on Benedryl last night and Allegra this morning. If they continue to get worse I think I will take him to a regular doctor and not the dermatologist just to get another opinion. He has 3 weeks left to go on the Claravis, but I don't think he'll make it if the hives keep coming back. I wonder if cutting the Claravis dose down and staying on a little longer would help?