The identification of biomarkers associated with psoriasis has the potential to predict susceptibility to psoriatic arthritis, provide evidence on natural history, therapeutic response and reveal pathogenic pathways that promote associated comorbidities. An increased inflammatory response has been documented in obesity, a condition that is associated with the occurrence and severity of psoriasis. Osteopontin (OPN), TNF and CXCL9 are increased in patients with psoriasis, although OPN has also been documented in the adipose tissue of obese patients without psoriasis. The prevalence of obesity is much higher in patients with psoriasis compared to the general population.