To fully understand psoriasis, you need to see what’s happening underneath the skin.
When your body has plaque psoriasis, your immune system is overactive, triggering skin inflammation and causing skin cells to be produced faster than normal. New skin cells are pushed to the skin's surface in 3 to 4 days instead of the usual 28 to 30.
But your body can't shed the new skin cells at that fast of a rate. So while new skin cells are being produced, the old, dead skin cells pile up on top of each other.
As more and more new skin cells are produced rapidly, the old skin cells are pushed to the surface, forming the thick, red, itchy, flaky patches known as plaques.
The exact cause of psoriasis is unknown.
Sponsored by AbbVie
My name is Alan Menter and my title is Chair of Dermatology and Chair of Psoriasis Research. Psoriasis is a disorder of the immune system, which is hyperproliferative. It is working too much, which then drives the skin to turn over too quickly, so instead of turning over in 28 days, say like the menstrual cycle, it turns itself over every 4 to 5 days, and so the cells just heap up on top of each other.
Psoriasis is a common disease that affects about 2% of the world population. It's a very varied disease; some people can present in different ways.
Psoriasis has multiple causes. It is certainly a genetic disorder. We have multiple genes up to 10 genes that have been shown to be present in psoriasis patients. The one or two, the common genes for psoriasis, so you're predisposed to psoriasis from birth, just like you have genes for breast cancer, or genes for diabetes, you have genes for psoriasis. These genes then have a specific impact on the immune system to cause and trigger inflammation into the blood vessels, which then get into the skin, which causes skin to get inflamed.
So yes, we have a very good understanding of the what we call the immunology and the genetics of psoriasis; what we don't yet know are all the trigger factors, just like you can have the breast cancer gene and never get it, something must trigger that genetic defect, so we have psoriasis patients that have all the genes for psoriasis but get very little psoriasis; others with the same genetic make-up get big-time disease, and we try to work out why.
Learn from a doctor about what causes psoriasis and what is happening inside your body when symptoms occur.
Dr. Menter is chairman of the Division of Dermatology at a prominent U.S. academic medical center. Dr. Menter is also a paid consultant of AbbVie.
Sponsored by AbbVie
Hello, my name is Dr. April Armstrong, and I’m a dermatologist. I’ve been treating psoriasis patients for 10 years.
In the U.S., up to 7.5 million people are affected by psoriasis. Of that 7.5 million, 80% have a type of psoriasis called plaque psoriasis, where thick, red, itchy, flaky patches called plaques form on the skin.
If you have plaque psoriasis, then you know it can be unpredictable and plaques can appear anywhere on your body at any time. Common areas are elbows, knees and shins, scalp, and lower back, but more “intimate areas” can be affected too, which you shouldn't be afraid to mention to your doctor.
One of the most common misconceptions I hear from my patients is that psoriasis is just a skin disease. If a patient comes in with red, itchy, flaky skin on her elbow, it's natural for her to assume she just has a skin problem, right? So it's up to me to change the way she looks at her psoriasis.
Those plaques you see on the surface of your skin? That's actually the end of the story. Let's start this story inside the body. If we look deeper into the body, we find that psoriasis starts underneath your skin. It's a complex, chronic disease that's the result of several factors, including genetics, environmental factors, and the immune system.
Your immune system keeps you healthy by fighting off illnesses, like a cold or flu. But what does that have to do with psoriasis? Back in the 1970s, scientists were working with patients getting organ transplants who also had psoriasis. When they gave them medications that toned down their immune systems, they found that some patients’ psoriasis improved.
So what happens in your immune system when you have psoriasis? While we don't know the exact cause of psoriasis, what we do know is that your immune system gets "turned on" by mistake, and then doesn't know how to turn itself off.
You see, there are small proteins in your immune system called cytokines. Think of cytokines as messengers between immune cells, such as T-cells. Everyone has cytokines throughout their bodies. But if you have psoriasis, at any moment your cytokines can start sending out messages that they shouldn't. And one of those messages is: make more skin cells than normal. And more. And more.
As more skin cells are made, they push to the surface of the skin, but then don't have anywhere to go, so they build up. That's when your skin can get red and inflamed, and become thick and flaky.
Since your immune system isn't confined to one spot in your body, there's no predicting where psoriasis will appear on the skin. But whether it's your elbow one month, and then your lower back another, the same thing is happening: skin cells are piling up on the skin's surface, and your body can't shed them as fast as you make them. The result is the only part of psoriasis you can actually see: a plaque.
Psoriasis is a chronic disease, meaning that it doesn't go away. Plaques may come and go, but your psoriasis is still there, active inside your body.
For some patients, their disease involves more than just the skin. Up to 30% of psoriasis patients – that's about 1 out of every 3 – can have a related disease called psoriatic arthritis, or PsA. What is PsA? Psoriasis plus joint pain. Remember the cytokines that cause red, flaky patches to form on your skin? In a similar process, messengers can also cause pain and swelling in your joints.
PsA can affect any joint in the body. Hands, fingers, and toes are typical, and you may also notice changes to the nails, like pitting. I've had patients tell me they feel stiffness or swelling everywhere from their lower backs and knees to their wrists and ankles. And many of them have noticed stiffness in their joints when they wake up, which can last a while. And that can be a typical sign of PsA.
So as you learn more about your psoriasis, if you start to experience pain in your joints, be sure to tell your doctor right away. PsA is a serious condition, and it can get worse over time if you don’t manage it properly, so it's important to get an early diagnosis from your doctor.
When it comes to psoriasis, remember: an active immune system. Increased messages at any time. Psoriatic Arthritis. As we've seen, there's a lot more going on than what we can see on the outside. As you learn more about your psoriasis, don't forget the inside story.
Understand how psoriasis starts inside the body, before you see it on your skin.