Medical Mystery: Why were his daughter's hands blue?

My 15-year-old daughter Grace had been working hard on an oral presentation for her English class when I received a call from her. Usually she just texts when she needs a ride home or wants to know what's for dinner.  I was between patients, so I answered immediately.

"My hands are blue and I can't breathe," she cried, clearly in a panic. My heart dropped.

"Where are you?" I asked.

"Outside my class" she stammered.

"Get to the nurse's office, now," I ordered. "Right now."

I grabbed my stethoscope and raced out the clinic doors. I called the school, and an assistant principal answered. She told me Grace was scared, and her hands were pale and blue, but she was breathing easily. We agreed she didn't need to call 911.

Moments later, I hugged my daughter, wiped away her tears, and immediately listened to her lungs while I looked for any hives or swollen lips, signs of anaphylaxis, a life-threatening allergic reaction. Normal. Then I looked at her hands. Both pale, with the blueness concentrated around her knuckles.

We rushed to the car and I called our emergency room to say we were on our way.

Blue hands, normal respiratory exam, no skin rashes. The list of what could be causing abnormal blood flow to her hands was narrowing  -- and frightening.

Acrocyanosis is a discoloration of the extremities, almost always the hands, that has multiple causes. Life-threatening reasons for this symptom are those where oxygen levels in the body are decreased and include anaphylaxis, blood clots to the lungs,  carbon monoxide poisoning,  heart rhythm abnormalities, food or other objects stuck in the trachea, and severe anemia.

In the ER, my daughter was immediately placed on monitors and her oxygen level was checked. All normal. An EKG and blood tests were ordered to check for anemia and other conditions that can inflame blood vessels that inhibit blood flow to the hands such as lupus. Also, normal.

The final diagnosis from the ER was Raynauds phenomenon or idiopathic acrocyanosis, requiring follow up with a rheumatologist and a cardiologist.

I sent a picture of Grace's hands to a colleague, a pediatric rheumatologist who helped guide our visit through the ER. With my daughter fast asleep, her hands still blue; I checked my emails from the day, and immediately opened up one from the rheumatologist with the topic "green fingers."

Culled from an article written several years ago, it described a rare phenomenon where sweat interacts with a certain bacteria on the skin, usually the benign Corynebacterium. The ensuing chemical reaction causes blue, or sometimes black or red, discoloration in patchy areas on the skin. It's also been reported that people who work with copper can have a similar chemical interaction and discoloration.

Taking an alcohol pad and wiping the skin where the blue concentrates will confirm the diagnosis, pseudochromhidrosis.

It was late at night, so I waited until sunrise, cloth in hands, soaked with alcohol. "What are you doing?" she asked as I hovered over her bed.

"Trust me," I said as I wiped the cloth hard across her knuckles. The color that had mystified my daughter, her school, the ER, and me, transferred easily onto the cloth and I continued to wipe away her hands until it was all removed. I cancelled her specialist appointments, thanked my coworker for her email, and bought some antibacterial hand wipes in preparation for my daughter's next oral presentation.

Daniel R. Taylor, D.O., is an associate professor at the Drexel University College of Medicine and director of community pediatrics and child advocacy at St. Christopher's Hospital for Children.