Hives

google

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early 16th century (originally Scots, denoting various conditions causing a rash, especially in children): of unknown origin.

wiktionary

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Origin uncertain, but frequently connected with heave, even if such a derivation is phonologically difficult.

See hive

etymonline

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hives (n.)

c. 1500 hyvis "itchy condition of the skin," origin unknown. Some writers connect it with heave because hives erupt out from the skin, but the phonetics of that are difficult to explain.