Multidisciplinary Perspectives on the Management of Plaque Psoriasis - Episode 2
Mark Lebwohl, MD: I am curious to hear what you say about triggers for joint disease, because triggers for skin disease are well known.
There is the withdrawal of summer sun. When we hit November—the season we’re recording this in—when we hit December or even late October, patients start to come back with an exacerbation of the psoriasis, which is related to having less sun exposure. On the other hand, guttate psoriasis can be triggered by a strep throat. Other infections contribute to the development of guttate psoriasis, and then various forms of psoriasis can be triggered by medications.
For example, the withdrawal of systemic steroids is the most common precipitating cause of pustular and erythrodermic psoriasis. Lithium can generate plaque psoriasis and pustular psoriasis. Antimalarials have been associated with erythrodermic and pustular psoriasis and just a flare of general plaque psoriasis, so there are different triggers for different forms of psoriasis. Are there triggers for psoriatic arthritis?
Philip J. Mease, MD: Absolutely. One of the things that is interesting about the disease and makes a difference from rheumatoid arthritis, for example, is that there is more activity of the innate immune system activation initial phases. The frontline defense is warning signals saying that we’ve got an infection going on in the skin surface or an infection somewhere in the body, we’ve got an alteration in the gut microbiome that is triggering disease activity, we’ve got microtrauma to the tendon attachment, which leads to dendritic cell activation, the production of interleukin-23, the stimulation of other cells in the genetically predisposed individual. All those things can contribute through innate immune system activation.
Oftentimes the disease is either monoarticular or oligoarticular, meaning 1 or less than 5 joints are being involved initially, and sometimes, the sentinel joint, as we call it, may be a joint that has previously had damage to it. The microdamage leads to activation of the immune system.
Eventually, what happens with psoriatic arthritis is that it becomes polyarticular: More parts of the body are involved, it’s progressive in nature, the spine can get involved later on in the disease. The other thing that we see is associated manifestation. Other diseases that may be present in a genetically related fashion, including not only psoriasis and the musculoskeletal aspects but inflammatory bowel disease and uveitis are associated conditions that can become inflamed and activated along with a certain comorbidity that’s including cardiovascular disease and metabolic syndrome. There’s a whole canopy of issues that will ensue after that initial inciting event.
Mark Lebwohl, MD: The 1 thing I didn’t hear you say that I know you’ve seen and we’ve seen is that the withdrawal of systemic steroids can result in a massive flair of not just psoriasis but also psoriatic arthritis.
Philip J. Mease, MD: Yes.
Transcript Edited for Clarity