@Henley0 @Sarah977 @Laura2592
At first glance I thought "immature roach" but after enlargement and enhancement what I thought were antennae looked more like long hind legs similar to a cricket -- or flea.
Fleas are ubiquitous. All animals host them. As far as I know they can't live on human blood but they don't know that and they will try.
I'm sure that I have been bitten by fleas because I live and work with animals, but I don't react to the bites so I don't know.
Other people are not so fortunate.
There is also no evidence that the bug in the picture is responsible for the guest's complaint.
My best guess would be something picked up outside, such as chiggers. Or fleas.
Incidentally, witch hazel, Tiger Balm, "ChiggerRid" and other proprietary substances are effective for relieving the itchiest. Ask at the nearest pharmacy.