O/E: Symmetrical hyperkeratosis of both elbows. Knees perfectly normal as is the remainder of his cutaneous exam. He is moderately overweight.
Comment: I suppose we all see this entity on frictional sites, but rarely name it. The patient denies rubbing or scratching the area but was observed to lean on his elbows. A similar problem has been reported (see reference 1. below). I recommended starting with 5% Keralyt gel twice daily and may add tretinoic acid. I propose that this type of hyperkeratosis can follow pressure on bony prominences, such as is seen on the foreheads of devout Muslims who pray 5 times a day (2). Prayer marks in Muslims appear to be more common in diabetics (3). The patient described in this VGRD post could well have the metabolic syndrome. I wonder if this might be important. I'd appreciate your thoughts.