Remember that sun exposure is cumulative over your lifetime, and we all have differing tolerances. So it's entirely possible to be on a drug that sensitizes you, have no problems for months or years, and then start having problems. Also, skin cancer can appear with absolutely no previous symptoms.
That said, the dosage people with autoimmune disease take is much lower than what transplant patients take, so the risk is not as high.
Ulcerative colitis forum co-moderator
Moderate to severe left-sided UC diagnosed 2001.
Flared for 5 years, finally in remission with Remicade since March 2006.
Avascular necrosis in both shoulders is my "forever" gift from steroids.
Colazal, Remicade, Nature's Way Primadophilus Reuteri.
"My life is an ongoing medical adventure"