Cold-blooded: How chilly weather caused this woman’s blood to clump

A 70-year-old woman caught more than just a cold in the wintery chill of Upstate New York.
She presented to doctors with dizziness and this extensive purple rash two weeks after the onset of a respiratory infection.
The marbled skin discolouration was consistent with livedo reticularis, a condition caused by altered blood flow in the skin microcirculation.
Not stopping at a rash diagnosis, however, doctors also took the patient’s blood.