Condition hub · psoriasis
Psoriasis guide: diagnosis, treatment choices, joints, and phototherapy
I cover what psoriasis is, what needs prompt attention, and how the main treatment types fit together.
What brings you here today?
You do not need to move through these in order.
See what else it could be and how a clinician checks it, including nail or joint changes worth mentioning and what needs urgent care.
2 · I need clearer answersI was diagnosed and want to understand itLearn what psoriasis is, what is happening in the skin, whether it is contagious, and what the diagnosis does and does not predict.
3 · Understand the choicesCompare treatment categories without ranking themPsoriasis care can include supportive skin care, topical medicines, medical phototherapy, oral systemic medicines, injected biologics and infused biologics. Compare the separate skin and joint goals too.
4 · Prepare for careBuild a focused appointment agendaCover diagnosis, urgent changes, high-impact sites, joints, safety, follow-up, and access.
5 · Work through accessCheck home-phototherapy policy questionsRead the psoriasis-labelled payer summaries without treating a public policy as your benefit decision.
Already know what you came for? Every page on this site is listed by name in all topics.
Wider reading elsewhere: National Psoriasis Foundation resource library (opens in a new tab). Psoriasis education and support beyond this phototherapy guide.
A grounded starting point
Psoriasis is more than a visible patch.
Psoriasis can affect skin, nails, and joints, not just the patch you can see.
Psoriasis is a long-lasting immune-mediated disease that can affect skin and nails. Some people also develop psoriatic arthritis. Evidence Evidence A photograph or checklist cannot confirm the diagnosis or rule out another condition.
Generalized pustular psoriasis and erythroderma require same-day specialist assessment. Seek urgent clinical help for a sudden widespread pustular eruption or extensive, rapidly spreading redness. Feeling acutely unwell increases the urgency, but do not wait for fever or other systemic symptoms. Evidence
Psoriasis can have a high impact even when the affected area is small. This is especially true on the face, scalp, palms, soles, folds or genitals, or nails, or when symptoms, function, or distress are substantial. Evidence
One thing patients keep saying is that the site which bothers them most, often the folds or the genital area, is the one they never show.
I would ask whether supportive care or observation is reasonable for your current skin goals, and what changes should trigger review. I would also ask whether possible joint disease or urgent skin changes need separate assessment. Evidence
Last updated
Questions to take to your next appointment.
Save only the ones you want to ask.
What findings support psoriasis, and what remains uncertain?
Saving keeps this on your device and needs JavaScript, which is off in this browser.Do my joint, tendon, heel, digit, or nail symptoms need a separate assessment?
Saving keeps this on your device and needs JavaScript, which is off in this browser.Which treatment categories fit the goals and burdens that matter to me?
Saving keeps this on your device and needs JavaScript, which is off in this browser.
What the published evidence establishes
A narrow starting point, not a personal forecast.
Narrowband UVB is used for skin conditions including vitiligo and psoriasis. Evidence Evidence That does not establish whether it is appropriate for you or how your skin will respond.
Medical phototherapy can treat psoriasis in the skin. It does not treat joint inflammation and is not a treatment for psoriatic arthritis. Joint concerns need a separate clinical assessment. Evidence
What's known
- Narrowband UVB can treat psoriasis in the skin.
- It does not treat joint inflammation or psoriatic arthritis.
What's uncertain
- Whether it is appropriate for you, or how your skin will respond.
If phototherapy is on the table
The decision is only the beginning.
Use the part of the practical path that matches your next decision.
Evidence behind this page
Sources
Each evidence badge opens the source and its limits. The full list stays available 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.
- 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 a broad patient-facing map of topical treatment, phototherapy, oral systemic treatment and biologic treatment. Also supports that a doctor usually diagnoses psoriasis by examining the skin, scalp and nails, and by asking about itchy or burning skin, medications, family history, recent illness or severe stress, and joint tenderness. Also supports that a doctor may take a small skin sample to examine under a microscope to rule out other skin conditions that look like psoriasis.
What it does not support
It does not rank categories or choose treatment for a particular person. It does not list a blood test as part of diagnosing psoriasis itself, and it does not diagnose psoriatic arthritis.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown 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 bringing joint, tendon, swelling, stiffness and nail concerns to a clinician because diagnosis uses clinical assessment and may require further evaluation.
What it does not support
It is not an online screening result and cannot diagnose psoriatic arthritis from a checklist.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- British Journal of Dermatology (Goulden V, et al.)Guideline · Regulatory / guideline, tier 1Independent source
- Published
- SteadySkin last checked
What this source can and cannot tell you
What this source supports
It supports that traditional NB-UVB fluorescent lamps emit a narrow UVB band peaking around 311 nanometres. It backs wearing UV-protective goggles and keeping UV scatter off people nearby. It records the consent form naming goggles and the same clothing at each session. It also covers clinical uses, how it compares with other light treatments, safety limits including sunburn-type reactions, and the added safeguards home phototherapy needs.
What it does not support
It does not provide a personal treatment plan, approve a particular home setup, or replace the instructions for your own device. SteadySkin never reproduces its treatment schedules.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
- British Association of DermatologistsPatient education · Patient education, tier 5Independent source
- Published
- SteadySkin last checked
What this source can and cannot tell you
What this source supports
It supports a plain-language explanation that NB-UVB uses a small part of the UVB spectrum, is used for conditions including psoriasis, eczema, and vitiligo, and is distinct from sunlight or a sunbed. It also supports what a unit asks of its own patients during a course. It asks them not to sunbathe or use a sunbed for the whole of it, and to reduce sun exposure so that skin does not burn. It asks them to report a medicine, a cream, or newly exposed skin such as a haircut. It asks them to arrive without perfume, deodorant, aftershave or other cosmetics, because some of those raise light sensitivity and can leave patchy discolouration for months. It carries the unit’s own account of repeated courses. It states that the full risk of narrowband UVB is not known, and that roughly one in ten people in the UK develop skin cancer. It states that a review becomes usual practice past a stated number of treatments, and that many treatments can bring the wrinkling and discolouration of photoageing.
What it does not support
It is patient education, not primary evidence for an efficacy claim. Its printed next review date was June 2025 and it has not been updated since June 2022. It is therefore used only for what it plainly states, and never as current guidance. It is written for a UK hospital unit whose nurses examine skin at every visit, so it sets no rule for a device used at home. Its numbers stay in this record rather than in the copy. Those are the sun protection factor and star rating it names, the hours it names, the treatment count that triggers a review, and the multiple by which it estimates lifetime risk. That multiple is stated there as an assumption that narrowband UVB behaves like sunlight, not as a measurement.
Claim-specific review for this source is still in progress. Only the source-level evidence and limits are shown here.
About the SteadySkin app
The app currently supports vitiligo only.
You can use every psoriasis guide without the app. I built the app for vitiligo first, so download links stay on vitiligo pages.