To ask why an adult BCG Scar Suddenly Swollen and Raised?

[Toomuchtooyoung01]

OH has had itchy/blotchy skin for a few days. Not had anything different to eat/drink, no new washing powder or anything obvious.
Not concerned, until his old BCG scar has this evening suddenly become swollen and raised, like massively so. What is this?! Does anyone have any idea?! Had a look online and cant see anything relevant! Thanks!

Is it just at the 3 sites of the bcg or is the arm in general itch and red?

Both arms are itchy and red, but the actual BCG site is a large, raised circular lump when it is usually flat and non remarkable.

Covid rash? Get a test?

A case of 29 year old immunocompetent female with delayed BCG granulomatous reaction presenting years after immunisation is described

article.sapub.org/10.5923.j.cp.20120101.01.html

This is the only thing I could find about BCG site becoming itchy years after.