tests to expect
with psoriasis and how they work
Skin or nail culture
2
Skin biopsy
1
Blood and urine tests
4
Wood’s lamp examination
3
Blood pressure tests
5
Imaging tests
6
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A doctor might order a skin biopsy to rule out
other conditions that can cause symptoms similar
to psoriasis.
First, they will disinfect and numb an area of the affected skin. Then they will use a small tool to remove a skin sample, which an expert will examine under a microscope.
Skin biopsy
Certain bacterial, viral, and fungal infections can cause symptoms similar to psoriasis.
A doctor may order a skin or nail culture to check for infections. They will use a small tool to collect a sample of skin cells, fluid, or a nail, which they will send to a laboratory for analysis.
Skin or nail culture
Wood’s lamp examination is another test a doctor may use to check for certain bacterial or fungal infections.
They will ask a person to sit in a dark room and
hold a Wood’s lamp by their skin. This lamp emits ultraviolet light, which causes some types of bacteria and fungi to glow.
Wood’s lamp examination
A doctor may prescribe systemic treatments for moderate to severe psoriasis or psoriatic arthritis.
These treatments carry a risk of side effects, and some of them are unsafe for pregnant people or people with certain infections. A doctor will order blood and urine tests before and during treatment to learn whether the treatment is safe and check
for signs of side effects.
Blood and urine tests
Certain systemic treatments for psoriasis can raise
a person’s blood pressure.
A doctor will use an inflatable arm cuff with a blood pressure gauge to check their blood pressure during appointments. They may also encourage the person to monitor their blood pressure at home.
Blood pressure tests
If someone develops joint symptoms, a doctor may order a combination of blood and imaging tests to check for signs of psoriatic arthritis or other joint conditions.
The imaging tests may include ultrasound, X-ray, CT, or MRI scans of the affected joints. The doctor will order regular follow-up tests after diagnosing psoriatic arthritis to monitor how it affects the joints.
Imaging tests
6
