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Wiktionary
favid

n. (lb en diseases) An allergic reaction in the skin observed in patients who have favus, which is a type of tinea capitis.

Wikipedia
Favid

Favid (of "favus" Latin for "honeycomb" is a disease usually affecting the scalp, but occurring occasionally on any part of the skin, and even at times on mucous membranes.

The word “Favid” is more used than French word “favus”, which is close to the Latin etymology.