A retrospective cohort study assessed the risk of lymphomas in patients treated with topical pimecrolimus, tacrolimus or moderate-high potency corticosteroids. Patients were chosen from a health insurance claims database from January 2002 to June 2006. A nested case-control analysis was also included. Of 98,585 pimecrolimus initiators, representing 121,289 patient-years, 26 lymphomas were identified, an incidence of 21/100,000 patient-years. This incidence was similar to that in tacrolimus and corticosteroids patients (relative risk, RR: 1.16 and 1.15, respectively). All three treatments were associated with an increased risk of lymphoma relative to the general population (RR: 2.89, 2.82 and 2.10 for pimecrolimus, tacrolimus and corticosteroids, respectively). This may suggest an increased detection of preexisting lymphoma. However, ...