What do clinicians measure over time?
The same few things, taken again. How much skin is involved, a score for the plaques, a clinician rating, and a questionnaire about your week. The useful part is the comparison, not any single reading. Evidence Evidence Evidence Evidence Evidence
Why this item matters
- Sources cited, not yet graded
The Psoriasis Area and Severity Index grades redness, thickness and scale against how much skin is involved. It comes out as one number, so it can be taken again and set beside the last one. Trial reports name a response by how far that number fell. PASI 75 means a score at least 75 per cent lower than at the start, or skin at least 75 per cent clearer. The reports of biologic classes I read take that response at week 12 to 16, some at PASI 75 and some at the higher PASI 90 bar. The International Psoriasis Council pairs body surface area with a physician global assessment. The Dermatology Life Quality Index asks ten questions about your last seven days and totals 0 to 30.
Check before moving on
- Depends on you
A percentage of skin is an estimate, not a measurement. The 1978 paper I read does not report how closely two clinicians scoring the same skin agree. Trial response rates describe groups, and you are one person. PASI 100 turns up in trial reports too, and I could not find a definition for it in the sources here. I set out what the instruments measure on how severe is yours, so I do not repeat that here.
Questions for your dermatologist
Which measure will you use to judge whether this is working for me?
Saving keeps this on your device and needs JavaScript, which is off in this browser.Can my score go in my notes each visit, so we can compare them?
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What does responding look like on skin?
It shows up feature by feature. The score grades redness, thickness and scale separately, so they are not obliged to move together. A plaque can flatten and shed its scale while a colored mark stays put. Evidence Evidence Evidence
Why this item matters
- Sources cited, not yet graded
NIAMS describes psoriasis patches as thick, red and scaly skin that itches or burns. Each of those is graded on its own, from 0 to 4. A flat mark left behind is not the same thing as an active plaque. On brown and black skin this matters twice. The systematic review of narrowband UVB in skin of color that I read reports hyperpigmentation after treatment as a known consideration. The same review notes that redness can be harder to see in some darker skin tones, which may lead to side effects going underreported.
Check before moving on
- Depends on you
I could not find which feature changes first, or how long a mark takes to fade, in any of these sources. The review covers Fitzpatrick skin types III through V, mostly from studies in Asia, and reports nothing for lighter skin. Separate grading is how the index is built, not a forecast for your skin. Telling an old mark from active disease is an examination, and your dermatologist does it.
Questions for your dermatologist
Is this a mark left behind, or is my psoriasis still active here?
Saving keeps this on your device and needs JavaScript, which is off in this browser.How would you expect my plaques to change if this is working?
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How long is a fair trial?
Long enough for the measure to move. Guidelines and trial reports describe marks in weeks, not days. Which mark applies to you is your dermatologist to set. Evidence Evidence Evidence Evidence
Why this item matters
- Sources cited, not yet graded
Whether to switch when a treatment stops working is one of the questions psoriasis readers ask most. The clinical-guidance summary of biologic classes I read reports PASI responses read at week 12 to 16. The health-technology review of two topical trials I read reports their results read at week 8. The International Psoriasis Council puts a mark for topical therapy in writing. It counts topical therapy as failed when skin has not reached clear or almost clear after two four-week courses in a row. NICE assesses the skin, the nails, high-impact sites, the effect on daily life and any joint concerns, rather than one reading alone.
Check before moving on
- Depends on you
A trial week mark is a measurement point, not a promise. I could not find how long your own treatment should run before anything changes. Trial populations are selected, and their week marks were chosen for the study. IPC is a professional consensus and sets no health plan rule. NICE is UK guidance and sets no US coverage rule.
Questions for your dermatologist
When will we decide whether this has worked?
Saving keeps this on your device and needs JavaScript, which is off in this browser.What would count as enough improvement for me to stay on it?
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Why do photos beat memory?
Because memory edits and a camera does not. Light, distance and how you stand change what a plaque looks like more than a single week of treatment does. Hold those steady and the difference you see is likelier to be real. Evidence Evidence Evidence
Why this item matters
- Sources cited, not yet graded
A comparable series keeps its conditions fixed. The same artificial light in the same position, rather than sunlight. The camera level, the distance the same, and the same body areas every time. Every picture carries its date. The National Psoriasis Foundation says to bring a symptom record to your appointment and share it, on paper or on a phone. Its flare guide offers a worksheet for daily symptoms and their severity. I put the full method on tracking flares and photos, so I do not repeat it here.
Check before moving on
- Depends on you
I took the camera method from a page written for vitiligo, a different condition, and only the technique carries over. It does not establish that photo tracking changes a psoriasis outcome. The NPF pages give no percentage or timeline for what tracking changes. A photograph records what the camera saw, and your dermatologist reads it beside the examination.
Questions for your dermatologist
Which areas would you like photographed before my next visit?
Saving keeps this on your device and needs JavaScript, which is off in this browser.What do you need to see from me to judge better or worse?
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Why record itch and sleep as well?
Because they can move while the plaques barely do, and because a review should hear about them. A quiet night is evidence too. Evidence Evidence Evidence Evidence
Why this item matters
- Sources cited, not yet graded
NIAMS lists poor sleep quality as a psoriasis symptom, beside patches that itch or burn. In a study of 200 people with psoriasis, those with worse itching had worse sleep on every measure checked. Higher severity scores lined up with worse sleep quality and shorter sleep. The Dermatology Life Quality Index already asks about symptoms and feelings, daily activities, leisure, work or study, and relationships. The American Academy of Dermatology records that treating the psoriasis itself is the most effective way to relieve itch.
Check before moving on
- Depends on you
The sleep study I read ran at one hospital in Egypt, with no comparison group and mostly mild-to-moderate cases. Sleep was measured by questionnaire, not in a sleep lab. It shows a pattern across a group, not a cause, and it predicts nothing about your nights. Bring the record and let the decision to stay or switch rest on it, together with the examination.
Questions for your dermatologist
Does my itch and sleep record change what you would do next?
Saving keeps this on your device and needs JavaScript, which is off in this browser.If my skin looks better but I still itch, what does that tell you?
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Evidence behind this page
Sources
Each evidence badge opens the source and its limits. The full list stays available here.
- National Institute of Arthritis and Musculoskeletal and Skin DiseasesPatient education · Patient education, tier 5Independent source
- Published
- SteadySkin last checked
What this source can and cannot tell you
What this source supports
Supports that poor sleep quality is a listed symptom of psoriasis. Also lists patches of thick, red, scaly skin that itch or burn, and dry, cracked skin that itches or bleeds. Supports that psoriasis carries risk for mental-health concerns including low self-esteem, anxiety, and depression. Supports that managing common triggers, such as stress and skin injuries, can help keep symptoms under control. Supports, by subtype, that guttate psoriasis outbreaks are often triggered by an upper respiratory infection such as strep throat. Also supports that pustular psoriasis symptoms can be triggered by medications, infections, stress, or certain chemicals. Also supports that erythrodermic psoriasis can be triggered by a bad sunburn or certain medications including corticosteroids. Also supports, by subtype, that inverse psoriasis appears as smooth patches of inflamed skin in skin folds. It names the armpits, the groin, and under the breasts as those folds. It records that rubbing and sweating can make inverse psoriasis worse.
What it does not support
Does not give a percentage of patients affected. Does not measure how much sleep is lost. Does not establish that treating the skin fixes the sleep problem for any one person. Its trigger information is organized by psoriasis subtype, not as one general list for plaque psoriasis specifically. It counts nothing for inverse psoriasis either. It gives no share of people affected in a fold or genital site, and it names no treatment for one.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- Scientific Reports (Zaky MS, Elgamal EA, Mohamed DH, Abd Al Maksoud AA, Elsaie ML)Observational study · Clinical research, tier 2Independent source
- Published
- SteadySkin last checked
What this source can and cannot tell you
Why the independence label says this: Government research-funding acknowledgment only (Egypt STDF/EKB); the authors state no competing interests.
What this source supports
Supports that in a study of 200 people with psoriasis, 16% had poor sleep quality overall. That rose to 50% among people with severe psoriasis and 25% with moderate psoriasis, against 11.8% with mild psoriasis. Supports that people with worse itching had much worse sleep on every measure checked. Supports that higher disease-severity scores lined up with worse sleep quality, shorter sleep, and more sleep disturbance. Both links were strong enough that chance alone is an unlikely explanation.
What it does not support
A single-hospital study in Egypt. It had no comparison group and mostly mild-to-moderate cases. Sleep was measured with a questionnaire, not a sleep lab. It shows a pattern across a group, not that itching causes poor sleep. It does not predict any one person’s sleep.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- International Psoriasis CouncilGuideline · Clinical research, tier 2Relevant relationship disclosed
- Published
- SteadySkin last checked
What this source can and cannot tell you
Why the independence label says this: The International Psoriasis Council names its corporate members on its own site (psoriasiscouncil.org/about/corporate-members/, checked 2026-09-11). The top tier names AbbVie, Johnson & Johnson, Eli Lilly, Novartis and Takeda. LEO Pharma, UCB, Almirall, Sun Pharma, Amgen, Alumis, Arcutis and Oruka sit below them. Those firms make the drugs this severity rule opens the door to. A wider rule on who qualifies is a wider market for them. The page says nothing about how that money relates to IPC independence.
What this source supports
Supports that IPC dropped the mild, moderate and severe scale. In its place a person is a candidate for topical therapy, or a candidate for systemic therapy. Supports that any one of three criteria is enough to be a candidate for systemic therapy. The first is psoriasis on 10% or more of the body surface. The second is psoriasis on a high-impact site. IPC names those sites as the face, palms, soles, genitalia, scalp and nails. The third is failure of topical therapy. Supports that IPC defines that failure in writing. It is not reaching clear or almost-clear skin after two four-week courses in a row. IPC gives clear or almost-clear as 1% or less body surface, with a physician global assessment of 0 or 1. Supports the source paper. It is Strober B, Ryan C, van de Kerkhof P, et al. Recategorization of psoriasis severity: Delphi consensus from the International Psoriasis Council. J Am Acad Dermatol 2020 Jan;82(1):117-122. Supports that IPC's own June 2025 teaching deck lists payers among the groups it set out to move. That deck also names refusal to pay as a result of the older scale.
What it does not support
Does not set any health plan's coverage rule. This is a professional-society consensus. It is not a regulation and not a plan document. Does not say which systemic treatment follows once a person meets a criterion. It sets no dose, no frequency and no schedule. Does not give the number of experts who voted, the response rate, or their conflict-of-interest disclosures. IPC's own June 2025 deck states the body-surface threshold two ways. Its criteria summary says 10% or more. The slide expanding that criterion says above 10%. Does not establish that a given reader meets a criterion. It predicts nothing about what a plan will decide.
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 treating the psoriasis itself as the most effective way to relieve itch. Supports moisturizing instead of scratching, especially after washing. Supports warm water, and showers of about 5 minutes or baths of about 15 minutes. Supports a cool, damp washcloth on itchy skin. Supports an anti-itch product with menthol or camphor as ingredients that tend to work well.
What it does not support
Does not quantify how much itch a given step relieves. Does not say an anti-itch product replaces psoriasis treatment.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- National Psoriasis FoundationPatient education · Patient education, tier 5Independent source
- Published
- SteadySkin last checked
What this source can and cannot tell you
What this source supports
Supports that tracking symptoms and common triggers over time can help a person figure out their own specific triggers. Supports naming stress, alcohol, and diet as examples of common triggers to watch for. Supports naming discolored skin patches and itching as psoriasis symptoms, and joint swelling and fatigue as psoriatic arthritis symptoms, to watch for. Supports using a worksheet to record daily symptoms and their severity, and sharing that worksheet with a health care provider.
What it does not support
Does not give a percentage or timeline for how much tracking changes any one outcome. Does not name every possible trigger - stress, alcohol, and diet are examples, not a complete list. Does not measure whether tracking itself helps or burdens a given person.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- National Psoriasis FoundationPatient education · Patient education, tier 5Independent source
- Published
- SteadySkin last checked
What this source can and cannot tell you
What this source supports
Supports bringing a symptom tracker, kept on paper or on a phone, to share with a doctor at an appointment. Supports clearly describing symptoms and noting changes in severity and affected areas as part of preparing for a visit.
What it does not support
Does not mention photographing skin changes specifically. The page shows no visible byline or update date. The site copyright year, 2026, is used here.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- MyVitiligoTeamPatient education · Patient education, tier 5Independent source
- Published
- SteadySkin last checked
What this source can and cannot tell you
What this source supports
Supports a solid-colored background for a comparable photo series. Black, green, or dark blue are named as ones that help skin stand out. Supports using the same artificial light in the same position each time, rather than sunlight. Supports holding the camera straight rather than tilted. Supports a distance of about 3 to 5 feet, held the same every time. Supports photographing a fixed list of body areas the same way every time. Supports using a ruler for scale and tagging each photo with its date.
What it does not support
Written and reviewed for tracking vitiligo, a different condition, not for psoriasis. Only the general camera technique - background, lighting, angle, distance, and framing - is used here; nothing about vitiligo itself is carried over. Does not establish that photo tracking changes any psoriasis outcome.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- Dermatologica 1978;157(4):238-244 (Fredriksson T, Pettersson U)Observational study · Supporting research, tier 3Independence not established
- Published
- SteadySkin last checked
What this source can and cannot tell you
Why the independence label says this: This 1978 paper is the first description of the Psoriasis Area and Severity Index. It is not open access. Any funding or competing-interest statement could not be read, and the study itself tested a drug.
What this source supports
Supports that the Psoriasis Area and Severity Index was first described here. Supports that the index scores three features of the skin: redness, thickness and scale. Supports that each of the three is graded on a scale of 0 to 4. Supports that the amount of skin involved is graded separately, on a scale of 0 to 6. Supports that the body is divided into four regions: the head, the upper limbs, the trunk and the lower limbs. Supports that each region carries its own weight, because each holds a different share of the skin. Supports that the four region scores are added, and that the total runs from 0 to 72.
What it does not support
Does not report how closely two clinicians scoring the same skin agree. Does not say how the redness grade behaves on brown or black skin. Does not set a score at which a person qualifies for any treatment. Does not say which health plans ask for the score. Does not diagnose a reader or predict what one person will score.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- Clinical and Experimental Dermatology 1994;19(3):210-216 (Finlay AY, Khan GK)Observational study · Supporting research, tier 3Independence not established
- Published
- SteadySkin last checked
What this source can and cannot tell you
Why the independence label says this: This 1994 paper is the first description of the Dermatology Life Quality Index. It is not open access, so any funding or competing-interest statement could not be read.
What this source supports
Supports that the Dermatology Life Quality Index was first described here. Supports that it is a ten-question form a person fills in themselves. Supports that every question asks about the last seven days. Supports that it was designed to be quick, and to be used in a routine clinic. Supports that the questions cover symptoms and feelings, daily activities, leisure, work or study, personal relationships, and the trouble of the treatment itself. Supports that each answer scores 0 to 3, and that the total runs from 0 to 30. Supports that a higher total means a heavier effect on life.
What it does not support
Is a first validation of a questionnaire, not a study of psoriasis treatment. Does not set a score at which a person qualifies for any treatment. Does not say which health plans ask for the score. A form about one week does not capture a better or worse week. Does not diagnose a reader or predict what one person will score.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- National Institute for Health and Care ExcellenceGuideline · Regulatory / guideline, tier 1Independent source
- Published
- SteadySkin last checked
What this source can and cannot tell you
What this source supports
Supports psoriasis assessment across skin, nails, high-impact sites, life impact and joint concerns; same-day specialist assessment for generalised pustular psoriasis or erythroderma; and a treatment map that includes topical, phototherapy and systemic options.
What it does not support
It is UK guidance and does not diagnose a reader, create a US treatment sequence, determine personal urgency from a description, or establish current US labeling or coverage.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- Canadian Agency for Drugs and Technologies in Health (CADTH)Systematic review · Clinical research, tier 2Independent source
- Published
- SteadySkin last checked
What this source can and cannot tell you
What this source supports
Supports the DERMIS-1 and DERMIS-2 phase 3 trial results at week 8: IGA success (clear or almost clear) in 42.4% (108 of 286) of the roflumilast group versus 6.1% (8 of 153) on vehicle in DERMIS-1, and 37.5% (99 of 290) versus 6.9% (9 of 152) in DERMIS-2. Supports PASI 75 (at least 75% clearer) in 41.6% versus 7.6% in DERMIS-1, and 39.0% versus 5.3% in DERMIS-2, both statistically significant.
What it does not support
This is a Canadian government health-technology-assessment review of the same pivotal trials the FDA reviewed, not a US regulatory document. It does not report results for any group narrower than the trial population as a whole (ages 12 and older), and it does not predict an individual result.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- PMC (National Library of Medicine)Systematic review · Clinical research, tier 2Independent source
- Published
- SteadySkin last checked
What this source can and cannot tell you
What this source supports
Supports a pooled PASI75 response rate of 70.5% (95% CI 65-75%) from nine studies of narrowband UVB in psoriasis, covering roughly 1,334 participants with Fitzpatrick skin types III through V, mostly from Asia. Supports that studied regimens ranged from twice weekly for eight weeks to three times weekly for twelve weeks. Supports that one included study reached 93.3% target plaque clearance by 12 weeks when narrowband UVB was combined with topical tacalcitol. Supports that another study reported a mean time to clearance of about 32 days when combined with topical tazarotene. Supports post-treatment hyperpigmentation as a reported consideration in darker skin tones, and notes that reduced visibility of erythema in some skin of color patients may lead to underreporting of side effects.
What it does not support
Does not report data on skin cancer risk or long-term safety monitoring, and does not report outcomes for Fitzpatrick I-II skin. Its pooled response rate should not be read as a prediction for every skin tone or population.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- HealioPatient education · Patient education, tier 5Independent source
- Published
- SteadySkin last checked
What this source can and cannot tell you
What this source supports
Supports week 12-16 PASI response ranges by biologic class, summarized from the joint AAD-NPF biologics guideline and related clinical literature. Anti-TNF agents: roughly 49%-80% PASI 75. The IL-12/23 drug ustekinumab: roughly 66%-75% PASI 75. IL-17 agents: roughly 77%-91% PASI 90. IL-23 p19 agents: roughly 70%-75% PASI 90. Supports that brodalumab’s label carries a boxed warning calling for regular evaluation of suicide risk, and that bimekizumab’s current US prescribing information includes a Warning and Precaution for suicidal ideation and behavior. Supports a general statement that TNF-class registries and studies warn that these medicines could potentially increase infection risk.
What it does not support
Is a secondary clinical-guidance summary, not the primary guideline document or a primary trial report itself. Does not report a single head-to-head trial comparing classes on the same PASI threshold, a specific reader’s risk, or cost.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.