Acrocyanosis, venous pooling of blood in the legs that causes them to turn blue, may be yet another symptom of long COVID, according to a case report published in The Lancet.

The case report features a 33-year-old man who for 6 months experienced blue legs after 10 minutes of standing, accompanied by a heavy, itching sensation. The legs returned to a normal color after 2 minutes of lying down.

The man had never experienced blue legs until his long-COVID diagnosis and subsequent diagnosis of postural orthostatic tachycardia syndrome (POTS), a condition that causes an abnormal increase in heart rate on standing. When lying down, the man's pulse was 68 beats per minute, but upon standing for 8 minutes, his pulse increased to a maximum of 127 beats per minute.

The authors of the report said there have been documented cases of acrocyanosis among children experiencing post-viral illness, but few cases have yet to be connected to long COVID.

"Patients experiencing this may not be aware that it can be a symptom of Long Covid and dysautonomia and may feel concerned about what they are seeing. Similarly, clinicians may not be aware of the link between acrocyanosis and Long Covid," senior author Manoj Sivan, MD, said in a University of Leeds press release.

###