A statistically higher risk for psoriasis or psoriasiform lesions during anti-TNF therapy was observed in female patients (OR 1.46, 1.23-1.73), those who are at a younger age at anti-TNF initiation (OR 1.03, 1.00-1.05), smokers (OR 1.97, 1.56-2.48), ileocolonic Crohn's disease patients (OR 1.48, 1.03-2.13), and those who are using adalimumab or certolizumab (<i>vs</i>. This evidence concerns the gene TNF and psoriasis.