I know this is a rather old topic, but I'd love to add my two cents. Because our son Dane is not yet diagnosed, my husband and I were desperate to try just about anything (already did the whole homeopathic route). Anyway, our derm thought it'd be a great benefit to Dane (2 at the time, now 2 1/2), to first try Methatrexate and then if that didn't have good results, to try Accutane. He told us the Methatrexate dose was about 1/50 the strength a cancer patient would take, so after much thought we tried it. Dane turned white after one dose, but lab results proved it was too hard on his liver (enzymes went up to 750, normal shouldn't be above 50). Thus, we tried the Accutane. We only saw improvements on his hands and feet (no more skin build-up), but it completely dried him out (which he is already) and he began to get even more bouts of MRSA (which he is still battling). We gave it the good 10 week trial, and took him off after he started whinsing when I'd pick him up. I'd bend down and gently pick him up from under his armpits and he'd say "OW Mama!". The derm tried to convince us to keep him on it, but we just took him off on our own. My husband and I are independent thinkers (my husband is an orthodontist, so he has a medical background along with his dental background). We really looked into and discussed the pros and cons of trying these treatments. I think it really comes down to the fact that we were just grabbing on to that last bit of "What if this is treatable" and gave it a shot. No more for us. Dane probably does have Netherton Syndrome (although he did not test positive), so the best thing for my family to do is to treat his skin as best as we can, wait it out, and continue to pray for a treatment for all forms of ichthyosis. I'm sure many adults are getting great results from the same treatment, but our bodies change so much from infancy to adulthood. If we could do it all over again, we would skip the trial and save it for another time.
Good luck. I hope this was of some help to you.