Psoriasis vs Seborrheic Keratosis

How to tell the difference — key features compared side by side.

Feature
Psoriasis
Seborrheic Keratosis
Category
Common
Benign
Key feature
Chronic autoimmune condition causing thick, silvery scaly patches. Affects 2-3% of the population. Not contagious.
Waxy, stuck-on growths - the most common benign tumor in adults over 50. Harmless but frequently mistaken for melanoma.
Risk factors
Family history of psoriasis (strongest risk factor); Stress (major trigger for flares); Obesity
Age over 50 (prevalence approaches 100% in elderly); Genetic predisposition (strong familial tendency); Sun exposure may play a role in some cases
Action needed
Persistent thick, scaly patches that do not respond to moisturizers
Only if you are unsure whether a growth is SK or melanoma

Psoriasis

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.

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Seborrheic Keratosis

Seborrheic keratosis (SK) is the single most common benign skin tumor, affecting nearly all adults over 60. They appear as waxy, raised, brown or tan growths that look as though they have been pasted or stuck onto the skin surface.

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Does yours look more like psoriasis?

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)?

Still not sure?

Our full ABCDE checker evaluates 5 clinical criteria dermatologists use.

Full ABCDE check →