In the Medical Letter article on ustekinumab (Stelara) for psoriasis (2010; 52:7), footnote 2 in table 2 should have included a second sentence: $5595.60 is the cost of one 45-mg syringe.

The FDA has approved the use of ustekinumab (Stelara - Centocor Ortho Biotech), an interleukin antagonist given by subcutaneous (SC) injection for treatment of adults with moderate to severe plaque psoriasis. It is the first agent in its class for this indication; the other biologic agents for psoriasis are Tcell or tumor necrosis factor (TNF) inhibitors.

The pathogenesis of acne is multifactorial: follicular hyperkeratinization, bacteria, sebum production, androgens and inflammation all play a role. The gram-positive microaerophilic bacteria Propionibacterium acnes promote development of acne lesions by secreting chemotactic factors that attract leukocytes to the follicle, causing inflammation.