Oddly enough, it's everything but jock itch. It began after we stayed at the Holiday Inn at Padre Island for a friend's wedding two years ago next month.
No, we live in San Antonio, 200 miles from Stinkadena.
Seriously, try the Aveeno anti-itch creme
Did he swim in the ocean at all?
First, check your bed. Lift up the sheets and check the very corners of the mattress. I'd also make sure to get a blood test specifically for thyroid as well as Lyme disease.
In the interim, try washing with unscented detergents and unscented fabric softeners.
Best wishes, a rash can be very frustrating.