Medically reviewed by Dr. A.M. van Coevorden, dermatologist
Bier spotsHarmless white spots that blanch under pressure.
Bier spots are small, irregular, pale to white spots on the skin, usually on the arms and legs. The surrounding skin often looks slightly redder or bluish. They are named after the German physician August Bier, who described the phenomenon in 1898. Bier spots are benign: they are a phenomenon of the small blood vessels in the skin, not a skin disease that causes damage.
What are Bier spots?
Bier spots are small, irregular, pale to white spots on the skin, usually on the arms and legs. The surrounding skin often looks slightly redder or bluish. They are named after the German physician August Bier, who described the phenomenon in 1898. Bier spots are benign: they are a phenomenon of the small blood vessels in the skin, not a skin disease that causes damage.
How do you recognise Bier spots?
You see many small white spots at once, in a mottled pattern. Characteristically, the spots disappear when you press on them or raise the arm or leg. They are often more visible in the summer months. Bier spots are most common between the ages of 20 and 40, and more often in women.
What causes Bier spots?
The exact cause is not fully known. Bier spots appear to result from an exaggerated but in itself normal reaction of small blood vessels. At the site of the spots, the vessels constrict strongly when blood pools, for example when an arm or leg hangs down for a while. This makes the skin there look pale, while the surrounding skin looks redder or bluer.
Are Bier spots dangerous and is treatment needed?
Bier spots are benign and chronic. No treatment is needed; explanation and reassurance are sufficient. Further testing is usually not needed when the picture and history are reassuring.
When should you see a dermatologist?
White spots on the skin can fit several conditions, such as vitiligo, pityriasis versicolor or pityriasis alba. A dermatologist can tell the difference, for instance because Bier spots blanch under pressure and disappear when the arm or leg is raised. Want certainty about white spots on your skin? Upload your photos and receive an assessment from a registered dermatologist within 12 to 48 hours.
Frequently asked questions
Are Bier spots dangerous?
No. Bier spots are a benign vascular phenomenon. They do not cause any damage to the skin.
Do Bier spots need to be treated?
No. Treatment is not needed; explanation and reassurance are sufficient.
Why do the spots disappear when I press on them?
Bier spots are caused by the constriction of small blood vessels. When you press on the skin or raise the arm or leg, the blood flow changes and the mottled pattern temporarily disappears.
How do I know it is Bier spots and not vitiligo?
A dermatologist can make that distinction easily. Bier spots disappear with pressure or when the limb is raised; other causes of white spots do not. Send in your photos for an assessment within 12 to 48 hours.
Sources and more information
- Bier spots (NTvDV 2016)