I used to have severe atopic eczema on my hands and fingers (it cleared up about a decade ago, before the fingerprint nonsense came in). Typically between 2 and 6 of my fingers at any time would be so swollen or inflamed that the fingerprint was distorted or entirely absent. This varied over time.

Eczema isn't that uncommon (although mine was pretty severe) and frequently affects the fingers and hands (as well as elbows and backs of knees). If the biometric-with-fingerprint passports had been standard back then I'd have been in a world of hurt, with fingerprints morphing over a period of multiple months.