I have to agree with the poster above me. However, stress can cause a person to be more susceptible to irritants than they may otherwise be during periods of relatively low stress. This could be caused by a mild allergic reaction to your laundry detergent. The best bet would be to schedule an opt. with your primary care physician.
Just a thought might not fit, but my sister had the same problem it turned out to has a thyroid problem, once she was put on medication the rashed stopped and so did the itchyness. good luck.
I thought it might be stress related, but I wasn't sure what hives looked like. I'll have to look in to it.
The very same thing happened to me but on my hand, the palms. Never did explain what it was and why but sometimes it appears and I am pretty stressed out when it appears. Just my experience.
Sounds like hives...either allergy or stress maybe. Sometimes this happens after a respiratory infection too, my doc explained this as the reason for my young son having hives on his arms and legs for 6 or 7 weeks.
Possibly but more likely it is an allergic reaction to something. Is it itchy? Does it itch when there is nothing there but after you itch the rash appears? They call that the "itch that rashes" and it is like hayfever but of the skin (that's how I think of it anyway).
It is unlikely to be anything too serious. Wait a bit and if still bothering you, see your doctor.
Good luck.