Is Dr Rich about?

[Burney]

Indeed. Here's what the French have to say about it: Le zona est une dermatose virale fréquente, due au virus de l'herpes zoster, le même virus que la varicelle. L'adjectif s'y rapportant est zostérien.

Basically, BGM is finnish.

I remember having to look up 'varicelle' when my daughter caught it on holiday in Provence one year