What is actually happening in the skin?
In psoriasis, immune cells that normally fight infection attack the skin's own cells by mistake. That signal tells skin cells to reproduce in days instead of weeks. The buildup on the surface is what becomes visible as a plaque. Evidence
Why this matters
- Sources cited, not yet graded
The American Academy of Dermatology traces this to T-cells - white blood cells that normally protect the body from infection. In psoriasis, T-cells attack healthy skin cells instead. The plaques, scale, and redness are the visible surface of that process, not the disease itself.
Considerations
- Depends on you
This describes the general disease process across large groups of patients, not why your immune system reacts this way or why a plaque appeared where it did.
Questions for your dermatologist
Does what you are seeing match a typical presentation, or is something atypical?
Saving keeps this on your device and needs JavaScript, which is off in this browser.Does the mechanism change which treatments make sense for me?
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Is it contagious?
No. Psoriasis is not an infection, and it cannot be passed to another person through touch, shared water, or close contact. Evidence
Why this matters
- Sources cited, not yet graded
The American Academy of Dermatology states this directly: psoriasis is not contagious. Unlike a cold or the flu, you cannot catch it from someone else - not through a shared pool, a handshake, or close contact.
Considerations
- Depends on you
This describes psoriasis in general; it does not confirm on its own whether what you are seeing is psoriasis rather than another skin condition that can look similar.
Questions for your dermatologist
If you are not sure this is psoriasis, what would confirm it?
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Why did I get it?
The best-supported explanation combines genes with an outside trigger. Neither alone fully explains psoriasis - some people carry the genes and never develop it, and family history is not required for it to appear. Evidence
Why this matters
- Sources cited, not yet graded
The American Academy of Dermatology describes psoriasis as running in families. Having a parent, grandparent, or sibling with it raises your own risk. But some people with none of the known risk genes still develop psoriasis, and other people carry those genes and never do. There is no single food, habit, or personal choice that explains why one person's immune system reacts this way and another's does not.
Considerations
- Depends on you
A family or genetic link is a population pattern, not a cause found in one reader’s own history.
Questions for your dermatologist
Does my history point to why this started?
Saving keeps this on your device and needs JavaScript, which is off in this browser.How much of this is established, and how much is still being worked out?
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What can set off a flare?
Common triggers include stress, a skin injury, certain infections, some medications, cold or dry weather, and smoking or heavy alcohol use. Which of these actually matters varies from person to person. Evidence
Why this matters
- Sources cited, not yet graded
The American Academy of Dermatology lists common triggers: stress, skin injury, infections such as strep throat, and certain medications, including lithium. Cold and dry weather, tobacco, and heavy alcohol use are also on the list. Not every trigger applies to every person - a clinician can help you notice which of these, if any, line up with your own flares.
Considerations
- Depends on you
The source gives no figure for how often any one trigger applies and does not claim its list is complete.
Questions for your dermatologist
Does my history point to a likely trigger, or is that not answerable yet?
Saving keeps this on your device and needs JavaScript, which is off in this browser.What would be worth tracking to find my own pattern?
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Does the diagnosis predict what happens next?
Not on its own. Psoriasis is typically a lifelong, relapsing condition: it tends to come and go rather than resolve permanently. How often, how severely, and where it shows up all vary widely, and none of that is predictable from the diagnosis alone. Evidence
Why this matters
- Sources cited, not yet graded
The American Academy of Dermatology notes that most people who develop psoriasis have it for life. Rather than a single fixed course, it tends to bring flares and periods of improvement. One named exception is guttate psoriasis in children, which can resolve on its own.
Considerations
- Depends on you
A general course description does not forecast severity, location, or how you will respond to treatment. Keep raising those questions at follow-up; they are rarely settled at the first visit.
Questions for your dermatologist
What would you expect to change over time, and what would surprise you?
Saving keeps this on your device and needs JavaScript, which is off in this browser.How will we know if the plan needs to change?
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Does psoriasis affect more than the skin?
It can. Psoriatic arthritis is the best-known example, and clinical guidance also links psoriasis with a higher likelihood of certain other conditions. None of this means any one person will develop them. Evidence
Why this matters
- Sources cited, not yet graded
The joint AAD-NPF comorbidities guideline names several conditions seen alongside psoriasis: psoriatic arthritis, cardiovascular disease, anxiety and depression. It also names a higher likelihood of diabetes, metabolic syndrome, and obesity. Having psoriasis does not mean you have, or will develop, any of these. It means they are worth mentioning to whoever manages your general health - especially joint pain, stiffness, or swelling, which can be easy to dismiss as unrelated.
Considerations
- Depends on you
A condition named in a guideline is not a diagnosis for one reader. The guideline's authors report industry relationships, and it is US guidance.
Questions for your dermatologist
My history includes ___. Is there something else worth screening for?
Saving keeps this on your device and needs JavaScript, which is off in this browser.Who should know about joint or mood symptoms - you, or someone else on my care team?
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Evidence and update context
This optional layer shows the evidence boundary I reviewed as of 2026-09-08.
- What this evidence supports
- The American Academy of Dermatology traces this to T-cells - white blood cells that normally protect the body from infection. In psoriasis, T-cells attack healthy skin cells instead. The plaques, scale, and redness are the visible surface of that process, not the disease itself.
- What it does not establish
- This describes the general disease process across large groups of patients, not why your immune system reacts this way or why a plaque appeared where it did.
Evidence behind this page
Sources
Each evidence badge opens the source and its limits. The full list stays available here.
- American Academy of DermatologyPatient education · Patient education, tier 5Independent source
- Published
- SteadySkin last checked
What this source can and cannot tell you
What this source supports
Supports that stress can trigger a psoriasis flare. Supports that skin injury - a cut, scrape, sunburn, tattoo, piercing, bug bite, or shaving nick - can trigger a flare near or at that spot. Typically this appears about 10 to 14 days after the injury. Supports that an infection such as strep throat, an earache, or bronchitis can trigger a flare, reported 2 to 6 weeks later. Supports that starting a medication - including lithium, antimalarial drugs, strong corticosteroids, or some blood pressure drugs - can trigger a flare about 2 to 3 weeks after starting it. Supports that cold, dry weather (such as winter or fall) can worsen flares, and that sunburn or spending time in air conditioning can also worsen them. Supports that smoking, or spending time around secondhand smoke, is a reported trigger. Supports that drinking daily, or more than two drinks on several days a week, can make psoriasis treatment have little or no effect. Supports that triggers differ from person to person.
What it does not support
Does not cite a specific study for its trigger list or timing windows, and does not state how many patients experience each trigger. This page displays no revision date; the date recorded here matches the same AAD psoriasis disease microsite's treatment-and-diagnosis page, checked the same day. Does not establish that avoiding a listed trigger will prevent a flare for any one person.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- Journal of the American Academy of Dermatology (Elmets CA, Leonardi CL, Davis DMR, et al.)Guideline · Regulatory / guideline, tier 1Relevant relationship disclosed
- Published
- SteadySkin last checked
What this source can and cannot tell you
Why the independence label says this: The guideline reports author relationships with industry. It is expert guidance, not independent proof for one person.
What this source supports
Supports that this guideline covers psoriasis alongside other health conditions. Supports naming psoriatic arthritis as one of them. Supports naming heart and blood vessel disease. Supports naming obesity, high blood pressure, raised blood fats and diabetes. Supports naming inflammatory bowel disease. Supports naming uveitis, an inflammation inside the eye. Supports naming depression and anxiety. Supports that it asks clinicians to screen people with psoriasis for psoriatic arthritis. Supports that it asks them to check heart risk factors. Supports naming body weight, blood pressure, blood fats and blood sugar among those checks. Supports that it asks them to screen for depression.
What it does not support
Does not diagnose a reader. Does not say which linked condition one person will get. Does not read a test result or set a personal plan. Its authors report industry relationships. It is US guidance. It does not set practice in another country.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- American Academy of DermatologyPatient education · Patient education, tier 5Independent source
- Published
- SteadySkin last checked
What this source can and cannot tell you
What this source supports
Supports that having a parent, grandparent, brother or sister with psoriasis raises a person's risk of getting it. Supports that people who have certain genes are more likely to get psoriasis. States plainly that some people who get psoriasis do not have genes known to raise the risk. Supports the immune-system account: white blood cells called T-cells are part of the immune system. In psoriasis, T-cells attack the body's own skin cells. That attack causes the body to make new skin cells much faster than usual.
What it does not support
It names no percentage of patients with a family history and no gene by name. This page displays no separate revision date; the date recorded here is the calendar year checked. It does not diagnose anybody and sets no genetic-testing recommendation.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- American Academy of DermatologyPatient education · Patient education, tier 5Independent source
- Published
- SteadySkin last checked
What this source can and cannot tell you
What this source supports
Supports that psoriasis is not contagious. States that, unlike a cold or the flu, you cannot catch psoriasis from someone. Supports that you cannot get it from swimming in a pool with someone who has psoriasis, and that touching someone who has psoriasis does not transmit it.
What it does not support
This page displays no separate revision date; the date recorded here is the calendar year checked. It does not address any other skin condition someone might also have, and it does not diagnose a reader.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- American Academy of DermatologyPatient education · Patient education, tier 5Independent source
- Published
- SteadySkin last checked
What this source can and cannot tell you
What this source supports
Supports that most people who get psoriasis have it for life. Supports that this holds true for every type of psoriasis with one named exception: guttate psoriasis in children, which can resolve on its own.
What it does not support
This page displays no separate revision date; the date recorded here is the calendar year checked. It does not forecast severity, location, or treatment response for one reader, and it does not diagnose anybody.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.