Cabbage dilemma!!

[DAVEM]

My red cabbages have been doing fine and so far I have cut two with good solid hearts.
Returning from a very brief absence I find some have developed raised bubbles across the outer leaves - white powdery deposit on both sides of leaf. Number greater on the outer leaves but clearly spreading to fast to inner ones. Have cut some smaller cabbages to save them.

Anyone know that this might be?

[Benacre]

Two fungi are responsible. Albugo candida produces the blisters, and a mildew Peronospora parasitica is the white powderey deposists you see.

Both are harmless but of course wash your cabbages firts in any instance

[DAVEM]

Many thanks Benacre for the technical explanation. Unfortunately they seem to be growing and spreading at quite a rate across the leaves and towards the hearts of the cabbages so as to make them unusable - or at least having to cut them too soon to be of real use.
Is there anything I can do to stop the spread.

Thanks.