Navarro R, Delgado-Jiménez Y, Guinea-Viniegra J, et al. - The authors conclude that the pathogenesis of paradoxical psoriasiform reactions and non-induced psoriasis is mediated by various pro-inflammatory cytokine profiles through conducting an analytic, cross-sectional, prospective, experimental case-control study.

• The sample consisted of 15 patients with a change of morphology (plaque to guttate psoriasis) and 10 patients with induced psoriasis (six palmoplantar pustulosis and four plaque psoriasis).

• As a control group, patients with various subtypes of non-induced, non-systemically treated psoriasis were included.

• They discovered that most cases of guttate psoriasis and induced plaque psoriasis had high TIMP-3 expression and low or poorly raised levels of miR-21.

• In cases of induced palmoplantar pustulosis, the expression pattern was not homogeneous.

• Such profiles vary from those of non-induced psoriasis.