A Blue-Fingered Diver in Warm Waters

Raynaud's phenomenon is a well-known consequence of exposure to extreme cold. Blood vessels constrict, and the fingers go blue. Constriction for too long is akin to frostbite, which can have severe consequences.

It's unusual to think of the ocean around Florida as sufficiently cold to cause it, but an un-named 18-year-old male, who made four dives to around 90 feet (27m) over two days, noticed a painless blue discoloration on three fingers of his left hand. It resolved within an hour of surfacing. During a medical examination one week later, everything appeared normal until medical tests showed blood flow was severely diminished in all digits of both hands when they were cooled. Since other causes were ruled out, the diver's blue fingers remained a mystery.

The doctors advised him to dive with gloves and a drysuit, wetsuit, or heated vest, even in tropical waters.

(Abridged from: Cable R, Weaver LK, Roberts AB, et al UHMS 2016, Vol 43, No7)