Yellow Tongue Leads to Rare CAD Diagnosis

A young boy’s bright yellow tongue led doctors to a diagnosis of cold agglutinin disease (CAD), as described in a report of this rare case.

The report, “An Icteric Tongue,” was published in The New England Journal of Medicine in the series Images in Clinical Medicine.

CAD is a rare autoimmune condition in which the body develops antibodies —  cold agglutinins — that destroy its own red blood cells (RBCs). Its symptoms  often include skin ulcers, a low RBC count called anemia, and dark-colored skin spots. As with many rare disorders, CAD can be challenging to diagnose, as it is not well known and its symptoms are not always specific to just that disease.

A 12-year-old boy was brought to the Hospital for Sick Children in Toronto, Canada, complaining of having a sore throat for four days, and experiencing dark urine, abdominal pain, and an unhealthy, pale appearance for the past three days.

A physical exam revealed a yellowing of the skin and eyes, a condition called jaundice, although in this case the jaundice extended to the boy’s tongue. Jaundice generally occurs when a waste product formed during the breakdown of RBCs, called bilirubin, builds up within the body.

The boy’s physicians ordered lab tests, which showed low levels of hemoglobin (the oxygen-carrying molecule found in RBCs) — 6.1 grams per deciliter (normal range is of 11.0 to 14.5). A urine analysis revealed the presence of hemoglobin, a potential indicator of anemia.

The team also found high levels of lactate dehydrogenase and bilirubin and the presence of cold agglutinins, all signs of CAD.

Viral infections sometimes cause jaundice and a test for one uncovered the presence of the Epstein-Barr virus (EBV), a fairly common childhood infection. Although its symptoms typically are mild or absent, EBV has been linked to some cases of autoimmune conditions, including CAD.

Doctors determined the boy’s anemia resulted from EBV-induced CAD.

Of note, CAD is rare in children, with the risk for the disorder generally rising after age 55.

The boy received a blood transfusion, along with high-dose intravenous methylprednisolone (a corticosteroid) over two days. The team then prescribed him oral prednisone in steadily decreasing doses over the next seven weeks.

“After discharge,” the researchers wrote, “he recovered well, and the tongue icterus [yellowing] gradually resolved as the bilirubin levels normalized.”