Psoriasis
Chronic autoimmune condition causing thick, silvery scaly patches. Affects 2-3% of the population. Not contagious.
What to look for
Side-by-side comparison
Normal skin
Smooth, clear
Psoriasis
Thick silvery scales on red
Psoriasis is a chronic autoimmune condition in which the immune system mistakenly accelerates skin cell growth. Normal skin cells mature and shed in about a month; in psoriasis, this process takes only 3-4 days, causing cells to pile up into thick, silvery-white scales on red, inflamed patches.
The most common form, plaque psoriasis, accounts for about 80% of cases and typically appears on the elbows, knees, lower back, and scalp. Other forms include guttate (small droplet-like spots, often triggered by streptococcal infection), inverse (smooth red patches in skin folds), pustular (white pustules on red skin), and erythrodermic (widespread redness covering most of the body - a medical emergency).
Psoriasis is not contagious - you cannot catch it from touching someone who has it. It is driven by genetic predisposition and immune system dysfunction. About one-third of patients have a family history of psoriasis.
Up to 30% of people with psoriasis develop psoriatic arthritis, which causes joint pain, stiffness, and swelling. Early recognition and treatment of psoriatic arthritis is important to prevent permanent joint damage.
Modern treatments have transformed psoriasis management. Options range from topical steroids and vitamin D analogs for mild disease to phototherapy, systemic medications (methotrexate, cyclosporine), and biologic agents (TNF inhibitors, IL-17 and IL-23 inhibitors) for moderate to severe disease.
Quick self-check
Does this look like psoriasis? Answer 2 questions.
Are there thick, well-defined patches with silvery-white scales?
Are they on typical psoriasis sites (elbows, knees, scalp, lower back)?
Risk factors
- Family history of psoriasis (strongest risk factor)
- Stress (major trigger for flares)
- Obesity
- Smoking
- Heavy alcohol consumption
- Certain medications (lithium, beta-blockers, antimalarials)
- Streptococcal throat infections (trigger for guttate psoriasis)
When to see a dermatologist
- ⚠Persistent thick, scaly patches that do not respond to moisturizers
- ⚠Joint pain or stiffness along with skin patches (possible psoriatic arthritis)
- ⚠Widespread or severe involvement affecting quality of life
- ⚠Skin changes that are worsening despite treatment
Often confused with
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Full ABCDE check →Frequently asked questions
Is psoriasis contagious?
Absolutely not. Psoriasis is an autoimmune condition driven by your own immune system. You cannot catch it from or spread it to another person through any form of contact.
Can psoriasis be cured?
There is no cure yet, but modern treatments can achieve near-complete or complete clearance of symptoms. Biologic medications have been transformative for moderate-to-severe psoriasis, with many patients achieving 90-100% skin clearance.
Does psoriasis affect joints?
Up to 30% of people with psoriasis develop psoriatic arthritis. Symptoms include joint pain, stiffness, and swelling, especially in the fingers, toes, and lower back. Early treatment prevents permanent damage, so report any joint symptoms to your doctor.