As the prisoner does when there's a rash of escapes (6,3)

'escapes' is the definition.
(breaking out is a kind of escaping)

'as the prisoner does when there's a rash' is the wordplay.
I cannot really see how this works, but
'as' could be 'so' (I've seen this in other clues) and 'so' is located in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
'a' is within the answer.
This may be the basis of the clue (or it may be nonsense).

'of' is the link.

Can you help me to learn more?