Blanching is considered a physiologic test. When blanching of the fingers occurs, it could be a telltale sign of a condition called Raynaud’s syndrome. But there are several other reasons that a person may experience blanching.
Blanching Test
A blanching test can be performed without any type of diagnostic tool. A healthcare provider presses the fingertips against the skin, exerting mild pressure for a short period, then quickly withdraws them, to check and see if whitening occurs.
Blanching can be tested by following a few simple steps including:
Press on the skin with your fingertips (select any suspicious areas, such as a red, darkened, or pink area)The area should turn white when pressure is appliedRemove the pressure from your fingertipsWithin a few seconds (after your fingertips are removed) the area should return to its original color (indicating that the blood flow to that specific area is good)
What Is Diascopy?
Diascopy is slightly more of an advanced technique to check skin blanching (compared to using the fingertips). This method of checking the blood flow to an area of the skin involves several steps, including:
Placing a piece of clear glass (such as a glass slide for a microscope) or clear plastic against the skin to view whether the skin blanches and fills properly under pressurePressing on the glass with the fingertips and viewing the color of the skin under pressureWithdrawing the fingersChecking to see if blanching occurs (note, blanching occurs when the area that has pressure placed on it turns whitish-colored but does not return to its original color (such as the surrounding tissue)
Signs and Symptoms of Blanching
The signs and symptoms of blanching include:
The skin appears white (or not as reddened) when pressure is appliedThe whitish color that appears when pressure is applied to the skin does not return to normal within a few seconds of removal of the pressureOften the skin appears cooler than normal if blood flow is occludedBluish discoloration of the skin may be present if blood flow is severely occludedNumbness or pain to the affected area
Causes of Blanching
There are several reasons that blanching occurs, from simple to more complex, these include:
Spider veins: Small damaged or “broken” blood vessels that often appear on the surface of a person’s legs or face; spider veins are not painful, they occur in a variety of disorders (such as rosacea, liver disease, sun-damaged skin, or pregnancy). Inflammation of the skin: This could include drug eruptions, hives, and more. Obstruction of blood flow to an area of the skin: Chemicals, cold, trauma, radiation, or chronic conditions can impair blood flow. Pressure sores: Skin abnormalities caused by unrelieved pressure, such as lying in the same position for extended periods. Frostbite: A condition caused by exposure to cold external temperatures in which there is a resulting loss of blood flow to the affected area. Raynaud’s syndrome: A condition that impacts approximately one-third of the people who have lupus (a condition that involves inflammation of the skin). It involves spasmodic constriction of the arteries and subsequent loss of adequate blood flow that usually affects the blood flow at the end of the fingers and toes. Bier’s spots: Small, irregular, hypopigmented macules that are usually found on the arms and legs. Livedo reticularis: A particular kind of skin discoloration, consisting of a reddish-purplish, web-like pattern that forms circles, typically on the legs or arms.
When To See a Healthcare Provider
There are some circumstances in which blanching of the skin is severe enough that a medical professional should be consulted. Call your healthcare provider when:
Skin ulcers are visible on the area of the skin that is blanched (particularly when the toes or fingertips are affected) You have severe pain and blanching of the skin You have any symptoms of anaphylaxis
Treatment
The treatment of blanching skin will vary greatly, depending on the underlying cause. Examples of types of treatment for blanching may include:
Spider veins: Treatment may involve a procedure called sclerotherapy (an injection into the veins of a solution that closes the spider veins). Raynaud’s syndrome: Treatment includes:Keeping hand warmers for winter useAvoiding cigarettes and caffeinated foods and beverages—which can worsen symptomsTaking prescription medications—such as nifedipine or amlodipine—to help dilate the blood vesselsPressure ulcers: There are many different treatment modalities for pressure ulcers, depending on the severity of the ulcer. Preventative measures include:Frequent repositioning and walking/exercising as much as possibleMassage to help improve blood flow to the affected area
A Word From Verywell
Blanching of the skin is not normal. If you have blanching, but are unaware of the underlying cause, it’s important to seek medical attention.
