I thank Whitmore for her interest in my study. As she indicates, exposure to high levels of methotrexate was the only therapeutic exposure associated with a higher risk of lymphoma among patients with psoriasis. Although our study included nearly 30 000 person-years of observation in a population that was relatively homogeneous with respect to severity of psoriasis, extent of exposure to other systemic therapies was too low for our study to have sufficient power to be likely to detect comparable levels of risk of lymphoma associated with other systemic treatments.
Stern RS. Methotrexate and Risk for Lymphoma—Reply. Arch Dermatol. 2007;143(5):659-675. doi:10.1001/archderm.143.5.664-a