Psoriasis is more than a skin condition – it’s an autoimmune disorder that speeds up skin cell growth, causing scales, redness, and inflammation. The Mayo Clinic describes it as “a skin disease that causes a rash with itchy, scaly patches, most commonly on the knees, elbows, trunk and scalp.” Over 125 million people worldwide, including 8 million in the U.S., live with this “common, long-term (chronic) disease” that can disrupt sleep, concentration, and overall health.

The exact cause is unknown, but genetics and environmental triggers play a role. The National Psoriasis Foundation identifies five main types. Plaque psoriasis is the most common, with thick, itchy patches covered in silvery scales, usually on elbows, knees, scalp, or lower back. Guttate psoriasis, often triggered by infections like strep throat, appears as small, teardrop-shaped spots on the trunk and limbs.

Inverse psoriasis shows up in skin folds, causing smooth, shiny red patches worsened by sweat or friction. Pustular psoriasis is less common but serious, with pus-filled blisters often requiring urgent care. The rarest, erythrodermic psoriasis, can cover the body with redness, pain, and shedding skin, and may be life-threatening.

Psoriasis can also affect nails, leading to thickening, discoloration, or detachment, sometimes signaling psoriatic arthritis. Recognizing symptoms early and seeking medical help is key to managing this chronic condition.