TNF and psoriasis: It has been shown that even if classical and paradoxical psoriasis have clinical similitudes, their pathophysiology differs; indeed, classical psoriasis is a T-cell mediated disease driven by TNF, by contrast paradoxical psoriasis is a type-1 interferon-driven innate inflammation.19 20 However, articular paradoxical manifestation pathophysiology remains unknown, some data suggested involvement of IL-12/IL-23 pathway.