Green’s Dictionary of Slang

dandruff n.

1. a head butt.

1989

(con. 1950s–60s) G. Tremlett Little Legs 92: I gave him the Glasgow Kiss or the Dandruff.

2. (US) light snow.

1975

L. Dills CB Slanguage.

SE in slang uses

In phrases

get one’s dandruff up (v.) [joc. corruption of the colloq. get one’s dander up + image of flecks of dandruff rising as one gesticulates with rage]

(US) to lose one’s temper.

1984		A. Sample (con. late 1950s-early 1960s) Racehoss 226: ‘I’m gonna call ya’ll by yore names afta I learn ‘em all. So don’ gitcha dandruff up if I say ‘hey you’ til I git a handle on ’em’.
2002		Bernice ‘Feeding goats milk to bottle calves’ posting 2 Mar. at Homesteadingtoday.com 🌐 And the thing that makes me so mad and get my dandruff up is folks or dairies that process milk and sell it to stores tasting yukky.