Chickenpox & flying/insurance

[missspeedy23]

Wasn't sure whether to post in health, travel or insurance so posting in all 3!

Chickenpox has been doing its rounds at my sons nursery and currently there's 4 children off with it. I've seen a couple of suspicious looking spots on him but the problem is we're due to go on holiday on Friday and just need some advice really. I know you can't fly until all the spots have crusted over and wouldn't particularly want to put someone else at risk by trying to disguise them but I'm not sure where we stand with our insurance.

We're travelling with my parents (who paid for the holiday) and we've got our own travel insurance that has cancellation cover. However, we don't really want to cancel but as we've booked everything separately and not a package is it possible to reschedule the flights/villa/transfers etc etc? Would the insurance cover the difference between the two dates as we'd not be able to go until August now and this will obviously be more expensive - although not as much as what they'd have to pay out for cancellation.

Has anyone else been in this situation? I just don't know what to do... we could try and fly on Friday but our insurance says we're not covered if our airline refuses to carry us for any reason - which I'm assuming this would class as if they refused to board us.

I'm absolutely gutted as we've been looking forward to it since we booked it in December ;(