Coexistence of Kaposi's sarcoma and psoriasis: is there a hidden relationship?

The relationship between Kaposi's sarcoma (KS) and psoriasis is still controversial. To analyse the association between KS and psoriasis, address the hypothesis of a reciprocal influence between the two conditions relative to clinical presentation and evolution, and consider the best therapeutic approach to be used for the treatment of psoriasis in KS patients in order to avoid the typical induction or worsening of KS during immunosuppression. We retrospectively reviewed clinical records of 37 patients with KS and psoriasis. Fisher's exact test was performed in order to compare epidemiological and clinical data between subsets of patients. The prevalence of psoriasis in our KS population (n = 1407) was 2.6%. There were no statistically significant differences in terms of stage or rate of progression between KS patients with and without psoriasis, except for a higher frequency of patients with KS Stage IIB among patients with KS and psoriasis (p = 0.001). Patients with psoriasis have a risk of KS comparable to that of the general population. Psoriasis and KS do not appear to influence each other. For the treatment of psoriasis in KS patients, one should take into account the KS-inducing potential of certain anti-psoriatic drugs.