With regard to patient preferences for those with mild disease, the standard dogma in dermatology used to be to give people greasy ointments. But many patients did not like these ointments and therefore did not use them, so they did not get well. For these individuals, I think that we have learned that the one vehicle that works better than all of the others is the one that a particular patient wants to use. For example, back in the 1990s, there was a topical therapy (a drying spray) that swept the world called Skin-Cap (SkinCap). Dermatologists were surprised to learn that the active ingredient was clobetasol, since they had already been prescribing clobetasol ointment with mixed success. We came to realize that the reason for success with Skin-Cap was primarily that patients were actually using the spray. That experience may have been a significant impetus for dermatologists to consider treatment adherence and its dramatic importance in the care of those with psoriasis.

Among the systemic agents, there have been some preference studies, but I find them difficult to interpret because, on the one hand, you are comparing apples to oranges to pears when you are comparing differences in efficacy, safety, and injection frequency. Another factor that I think limits the clinical value of those studies is that, generally, people often do not measure things in terms of their absolute reality very well. We tend to examine things by how they compare with something else. These studies indicate that patients might prefer a once-every-3-month dosing schedule over a once-per-month dosing schedule; however, if you were to ask them first if they would be willing have a daily injection for their psoriasis, my guess is that there would be very little difference in acceptance between once per month and once every 3 months. In this case, they would not be comparing once every 3 months with once per month, they would be comparing both of them with having an injection once per day. The differences between those 2 options would likely not be significant to patients once their brains are anchored on the idea of once per day.

The newer agents (ie, the interleukin-17 [IL-17] or the interleukin-23 [IL-23] drugs) are administered less frequently than the tumor necrosis factor (TNF) agents, for instance. While some patients may prefer the less frequent dosing with the newer agents, a compelling aspect from the clinician’s viewpoint is that the IL-17 and the IL-23 classes are likely more effective than most of the TNF inhibitors and are at least as safe. I think that the IL-17 drugs work faster, but they seem to have a relatively rare risk of inflammatory bowel disease development that you do not see with the IL-23 drugs. 

At this point, I believe that it is reasonable to ask the patient what they prefer. A doctor might have a strong preference for a particular agent over the other, but I would prefer to leave it up to the patients because they are the ones who are taking the risks and want the benefits. Some patients (eg, those who are younger and unmarried) may feel that they want to get better immediately and are willing to take more risks than, say, someone who is older and has been married for a long time and whose spouse is used to their psoriasis.