Transcript
Announcer:
Welcome to DermConsult on ReachMD. On this episode, we’ll learn about the manifestations of psoriasis and its various subtypes from Dr. Avery H. LaChance. Dr. LaChance is Director of the Connective Tissue Disease Clinic, Director of the Advanced Psoriasis Therapeutics Clinic, Director of Health Policy and Advocacy, and Program Director of the Dermatology-Rheumatology Fellowship at Brigham and Women’s Hospital. She’s also an Associate Professor of Dermatology at Harvard Medical School. Here’s Dr. LaChance now.
Dr. LaChance:
Psoriasis has a mean age of onset of 33 years, is more common in our white individuals, and impacts about two percent of the worldwide population. So it's really quite common when we think about our inflammatory skin diseases. And disease activity can lead to depression, social stigma, suicidality, and loss of sleep.
And it's important to know that the clinical presentation of psoriasis really varies by subtype and skin tone. So I think everyone is pretty comfortable with and commonly sees psoriasis. And what do we see? Psoriasis presents with these salmon-colored plaques with this overlying silvery scale, and these well-defined plaques that really hug over extensor surfaces—things like knees, elbows, and umbilicus.
I think that's the thing that's in all the boards and all the textbooks, but for some of our patients that have darker skin tones, sometimes it's more of a hyperpigmented plaque. You'll still see well-defined plaques with a silvery scale. But it's important to know that erythema can be more subtle in our patients with skin of color. So you're going to want to look for those classic locations: intergluteal fold, knees, elbows, umbilicus, and scalp. And if it looks a little more hyperpigmented in a patient with a darker skin tone, don't be fooled.
Now, there are also other subtypes of psoriasis. So we see things like guttate psoriasis, which is like little raindrops in smaller well-defined plaques with hyperkeratotic scale, but that's not as often as large plaques. But that can sometimes fool people as well.
There are other subtypes. We see palmoplantar disease. We can see nail psoriasis, where patients can either get pinning, oil spots, or hyperkeratotic nail changes. And so looking at a patient's nails is really critical to helping either diagnose psoriasis elsewhere on their body or to think about nail psoriasis and joint disease as well.
We can see sebopsoriasis, where psoriasis is in the scalp and overlaps with seborrheic dermatitis. And then there are also rare subtypes, like erythrodermic psoriasis or pustular psoriasis, and having that on your differential for a patient that comes in who's studded with pustules or is bright red head to toe is also very important.
Now, the rheumatology population will be very familiar with the fact that 30 percent of patients with psoriasis are going to develop psoriatic arthritis. And it's very important to know that patients with psoriasis can develop psoriatic arthritis at any time point. So when you diagnose psoriasis, your job is not done when you ask about their joints at their first visit. You're going to want to ask about joints at every single subsequent visit from there out.
And so for psoriasis, it's really characterized, again, by these well-defined plaques, silvery scale, predilection for extensor surfaces, extensor joints, umbilicus, intergluteal fold, and nails. We want to think about special sites for patients like groin, hands, and feet, and then also inverse disease in the axilla. And then know that skin tone and disease subtype can really impact appearance. And one last pearl on psoriasis is that scalp disease and nail and genital involvement can increase risk for PsA as well.
Announcer:
That was Dr. Avery H. LaChance discussing the characterization of psoriasis and its different subtypes. To access this and other episodes in our series, visit DermConsult on ReachMD.com, where you can Be Part of the Knowledge. Thanks for listening!
