The dermatologist we saw said, and anecdotally on this forum concur, that antiTNFa drugs (Humira and Remicade) can paradoxically cause drug induced psoriasis. Paradoxically, because both of those drugs are used to treat psoriasis as well. The dermatologist predicted H would clear up after moving to Stelara and she did. Stelara works through the IL-12 and IL-23 pathways but how that differs from TNF - I don't really know.