When to reintroduce banana?

[GiraffeAHolic]

When dd was first weaned her absolute favourite was banana.

However when she fed herself it and then wiped her face or touched her neck, the skin went red hot and very blotchy.

Because of this I stopped giving it to her as`the reaction was quite severe.

When should I start trying again with it?

Or should I touch a little bit on her skin to see if it still reacts?

How old is she now?
DS also had a similar reaction to banana. He was about 3 before I tried him with it again, and he was fine then.

She's only 7.5 months now, I might leave it a little longer then.