hello,
Thanks for the query.
Sudden appearance of rash can be due to two things.
1.urticaria
2.Menopausal flush

According to me, it appears to be urticaria.
menopausal rash is not that itchy and not so sudden, also mainly the face is involved.

Urticaria might have occurred due to contact with certain object such as flower,or it might be due to intake of a new food material.

For instant relief she can take an antihistamine like pheniramine and apply calamine lotion. She can take Tablet Pheniramine 25 mg 1 tablet and see how it goes.

You could probably post a picture of the lesion, so that I can comment specifically. You have a feature to upload the picture by yourself on the right side of this query page. You may want to utilize it

Let me know if you have any more questions. I would be happy to help

Thank you

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