LAUSR

Society for Publication of Acta Dermato-Venereologica The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signal ling pathway is one of the most frequently deregulated signalling pathways in malignant tumours (1). Likewise, the PI3K/mTOR pathway regulates both the innate and the adaptive immune response (2). Preclinical and clinical evidence have supported the principle of targeting this pathway, leading to the development of several inhibitors for the treatment of cancer. We report here a patient under treatment with a PI3Kdelta inhibitor, who presented a psoriasiform skin eruption. The rationale of PI3K inhibition is beneficial for psoriasis (2, 3) and observation of this unusual adverse event is probably a new example of an unexpected paradoxical psoriasiform reaction.