Hard to say, though nothing serious comes to mind. Since both of you have this, a viral infection seems most likely--many of the ones which affect the skin don't produce internal symptoms. The best approach would be to wait it out. Viral rashes often peel. If it worsens in either of you, I suggest seeing s skin doctor. But I doubt you'll have to.
Best.
Dr. Rockoff
This list: http://www.valdezlink.com/gwv/symptoms.htm
For myself, I notice a recurring rash when I get too much of a chemical (like a medication I get maxed out on) on my side. This is where in years prior I had leaned over the bathtub to wash it, & got the cleaning chemical on my blouse.
Anyway, there is something very significant about what you share as to flu-like symptoms. That is how exposure to 2-butoxyethanol or n-butyl ethers always seems to show up (with acute exposure anyway)
http://home.gci.net/~blessing/pages/flu.htm
http://home.gci.net/~blessing/pages/gwvsymptoms.htm#daughter
http://home.gci.net/~blessing/pages/aerosol.htm#aerosols
If so, what were you doing at that time?
Blood would show up in urine in 15 minutes and in 2-3 days a very elevated retic rate would be obvious from autoimmune hemolytic anemia. This is the fatigue doctors are looking for in CFS, CFIDS
www.valdezlink.com/check_blood.htm#retic
Was someone painting in the house?
http://www.valdezlink.com/pages/paintingjoints.htm