AKA urticaria in medical parlance. The topic came up in a room full of MD’s today and nobody had a clue. Even my Stedman’s Medical dictionary was of no use.
The most obvious possibility is that the name somehow originates from an associatiation with bees. I doubt it, though. While some individuals develop hives secondary to beestings, much more commonly, hives are associated with a food allergy or viral infection. And there’s no way the condition is named for its likeness to beehives. To verify, check out the image here.
Well, the original OED had no better clue than the rest of you. Its earliest citation is from a Scottish list of ailments.
Someone named Jamieson speculated that it came from heave since the rash “heaves up” from within the skin. The OED, however, notes that this is phonologically improbable (meaning that the way the word was originally pronounced in the region where it was originally recorded, it is unlikely that the the long E sound in heave would shift to the long I sound of hives).
BTW, if hives/urticaria always manifests as the low, lumpy, reddish-brown eruption in your linked photo, I would agree that it is not connected to beehives.
However, I have seen another rash (on the hand and wrist) in which the skin did, in fact, erupt into small, conical shapes quite similar to old-fashioned beehives. Is it possible that the name, once associated with a specific (descriptive) condition came to be applied to a broader list of conditions and lost its initial value? (Mind you, I have no supprt for this WAG from any reference I have checked.)