Bier spots are small, pale skin patches caused by temporary changes in blood flow through the small blood vessels. They are a benign vascular response rather than a loss of skin pigment or an infectious skin disease.
The spots are usually painless and do not itch. They most often appear on the arms or legs, become more visible when a limb hangs downward and fade when the limb is raised or pressure is applied to the skin.
Most cases do not require treatment and remain harmless. A medical evaluation may be recommended when the spots appear with swelling, circulation problems or other symptoms that could suggest an underlying venous, lymphatic or systemic condition.
Main symptoms
Bier spots usually cause a temporary change in skin color without discomfort.
The most common symptoms and features include:
-
Small, irregular pale or white-looking spots
-
A mottled or speckled pattern on the skin
-
Spots that are more noticeable when the arm or leg hangs downward
-
Spots that fade or disappear when the limb is raised
-
Spots that disappear or become less visible when pressure is applied
-
Red or flushed skin between the pale areas
-
No pain, itching, scaling or inflammation in most cases
-
More frequent involvement of the arms and legs
The appearance may change during the day depending on body position, blood flow and pressure in the veins.
Common causes
Bier spots develop because blood flow is distributed unevenly through the small vessels near the surface of the skin. The exact mechanism is not fully understood, and many cases are considered idiopathic, meaning that no specific underlying cause is found.
One theory is that some small blood vessels constrict more strongly than the surrounding vessels. These narrowed vessels temporarily reduce blood flow to small areas of skin, creating pale spots against a redder background.
Venous stasis may also contribute. When an arm or leg hangs downward, blood can collect in the veins, triggering a reflex that changes blood flow through nearby arteries and small vessels. This helps explain why Bier spots become more visible in a dependent limb and fade when the limb is elevated.
In some people, Bier spots have been reported with conditions that affect venous or lymphatic circulation, including lymphedema and venous disease. Associations have also been described during pregnancy and with certain systemic conditions, although the spots are harmless and isolated in most cases.
Confirming a diagnosis
The diagnosis of Bier spots is usually based on the appearance of the skin and how the spots respond to changes in position. A doctor may examine the affected limb while it is hanging downward and then raise it to see whether the pale areas disappear.
Another useful finding is blanching or fading when pressure is placed on the skin. The combination of temporary pale macules, greater visibility in a dependent limb and disappearance with elevation or pressure strongly supports the diagnosis.
Tests are not usually necessary. Additional evaluation may be considered when the presentation is unusual or when swelling, pain or other symptoms are present. Conditions such as vitiligo, tinea versicolor, post-inflammatory hypopigmentation and other pigment or vascular disorders may need to be ruled out.
Treatment options
Most Bier spots do not require medical treatment. They are benign, do not damage the skin and usually do not lead to complications.
When Bier spots occur with lymphedema, venous insufficiency or another circulation problem, treatment focuses on the underlying condition rather than the spots themselves. Management may include compression therapy, weight management and other measures recommended by a doctor to improve venous or lymphatic circulation.
There is no medication, cream or procedure that is routinely recommended for isolated Bier spots.
When to see a doctor
Medical evaluation is recommended when the diagnosis is uncertain or when the spots do not fade with elevation or pressure. An appointment may also be appropriate when the skin changes are new, widespread or becoming progressively more noticeable.
Assessment is especially important when Bier spots appear with limb swelling, pain, warmth, numbness, weakness or signs of poor circulation. These symptoms may be related to another vascular or lymphatic condition that requires treatment.