Psoriasis is generally diagnosed through a physical examination. Diagnosis of psoriasis is most commonly performed by a dermatologist.

Psoriatic arthritis is usually diagnosed by a rheumatologist. Diagnosis of psoriatic arthritis may involve imaging scans and blood tests.

How Is Psoriasis Diagnosed?

Typically, the dermatologist will diagnose psoriasis by visually inspecting the affected skin. The doctor may ask about family history and other symptoms you are experiencing during your visit.

In some cases, the doctor may want to confirm the diagnosis by performing a punch biopsy — removing a small piece of the skin for histologic examination. The biopsy sample is sent to a lab where it is observed in more detail under a microscope, and characteristic findings can confirm the diagnosis.

While there is no one conclusive test for psoriatic arthritis (PsA), diagnosis may involve a physical examination, blood tests, or imaging procedures such as X-rays and computed tomography (CT) or magnetic resonance imaging (MRI) scans. Scans allow the doctor to check for joint damage. Blood tests establish how much inflammation is in the body and help the specialist distinguish psoriatic arthritis from other conditions with similar symptoms, such as rheumatoid arthritis (RA). Skin psoriasis makes a diagnosis of PsA more certain, but the presence of certain blood proteins may point to RA. If arthritis is found symmetrically on both sides of the body, this may also indicate RA.

What Is the Prognosis for Psoriasis?

While symptoms may appear during disease flares and subside during remission periods, psoriasis itself is a chronic condition for which there currently is no cure. However, there are effective treatments for many symptoms of psoriatic disease.

Psoriasis and psoriatic arthritis (together referred to as psoriatic disease) are rarely life-threatening. However, people with psoriatic disease have a higher risk for developing diabetes and heart disease. It is important that people with psoriasis and psoriatic arthritis maintain a healthy weight, eat a nutritious diet, and get regular exercise to avoid developing these dangerous complications.

At What Age Does Psoriasis Start to Develop?

In the majority of cases, psoriasis begins either between ages 20 to 30 or between ages 50 to 60. However, psoriasis may develop in people of any age, even young children and infants.

Condition Guide

• Psoriasis — An Overview
• Types of Psoriasis
• What Causes Psoriasis?
• Symptoms of Psoriasis
• Treatments for Psoriasis
• Conditions Related to Psoriasis
• Eczema vs. Psoriasis: Are They One and the Same?