Oh brother, there goes the thread. Well LH, he did wait ;)
Another, less serious Dutch name for the infliction is ‘tenenkaas’ (toe cheese). That sort of resembles the German ‘Käsefuß’ you mention which I suppose is also not the official name.
Edit: what might be interesting is that the cheese references in Dutch and German may be related to the cheesy smell often associated with athelete’s foot. A chemistry teacher once told me that smelly feet are caused by bacteria that produce butyric acid which is indeed the same acid that gives cheese its particular odor.