THE OFFICIAL NEWS SOURCE OF ACR CONVERGENCE 2022 • NOVEMBER 10-14



Color changes to digits can indicate many things

Most rheumatologists don’t focus too much on vascular biology — except on those days, most often in winter, when they encounter the patients whose fingers have changed color.

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Nicholas Flavahan, PhD

“The vascular system is an essential and highly integrated system in the body, but it is spread around several different disciplines,” said Nicholas Flavahan, PhD, Edward D. Miller Professor and Vice Chair for Research in Anesthesiology and Critical Care Medicine at The Johns Hopkins University. “The vascular system of the heart is dealt with by cardiologists, whereas rheumatologists generally focus on the peripheral vascular system. All of the color changes in peripheral tissues that rheumatologists see and manage are a function of changes in the vascular system and vascular biology. Every time you see a patient whose fingers or toes have gone red or white, or blue, you are dealing with vascular pathobiology.”

Dr. Flavahan will join two other presenters to discuss The Red, the White and the Blue: Digital Color Changes and the Rheumatologist today from 2:30 – 4:00 pm. Some color changes are relatively benign, and some may be caused by pathologic disorders such as erythromelalgia, which can cause visible redness, intense heat, and burning pain.

“Seeing fingers or toes turn blue or white can be a scary event for patients and prompt a visit to a provider,” said Robyn Domsic, MD, MPH, Assistant Professor of Medicine at the University of Pittsburgh. “There is the acutely blue finger that shows up in the ER and has one set of likely possibilities on differential. And then the recurring or episodic blue finger which one encounters in clinic and has another list of likely possibilities. An important thing to remember is that not every recurring blue finger is Raynaud’s phenomenon.”

It can be easy to overlook the vascular system, Dr. Flavahan said. Almost everybody typically considers cardiac disease to be the number one killer of humans, but the primary underlying cause of that pathology is actually vascular disease. Atherosclerosis, a vascular disease, typically triggers myocardial infarction and stroke by inducing ischemia. Depending on the particular vascular condition and the patient’s underlying condition, pathologic vascular changes may produce red skin, white skin, blue skin, or a combination of all three as circulation changes.

“The vascular system is highly complex and interconnected,” he said. “Blood flow in the skin is similarly complex and is regulated unlike any other vascular compartment. My job in this symposium is to provide a mechanistic understanding which explains the symptoms rheumatologists are seeing and can help provide clues as to how to manage those symptoms.”

Christopher Denton, MBBS, Professor of Experimental Rheumatology at University College London Medical School, will discuss the diagnosis and management of erythromelalgia.

Dr. Domsic will discuss differential diagnosis and management of digital ischemia, which can turn digits white, then blue, and sometimes red as perfusion returns.

“Raynaud’s can be a symptom of scleroderma and other rheumatologic conditions such as Sjögren’s, but there can be multiple reasons digits turn blue, not just Raynaud’s,” Dr. Domsic said. “As a rheumatologist, it is important to recognize the difference between Raynaud’s, acrocyanosis, and an acutely ischemic digit.”

Cold is the biggest give-away, she said. Particularly in winter, look for cold exposure as a cause of color changes and ischemia. It also helps to check on the extent of color change. Blue-tinted fingers may be Raynaud’s, but a blue hand almost certainly is not.

“If you spend two or three minutes and get a good history, you can narrow your differential diagnosis substantially,” she said. “You might start with 10 people who are convinced they have Raynaud’s and five minutes later you’re down to a smaller number who actually have it.”