From your description, you may indeed have hives. Hives can last for weeks or months. Treating them with antihistamines, as you are doing, plus over-the-counter itch preparations like Sarna is a reasonable approach. The bruises are no doubt from scratching, and hives really itch.
Hives are not contagious. I don't know what your wife has. Your description sounds nothing like scabies.
If your symptoms and those of your wife persist, you should show them to a doctor in person.
Take care.
Dr. Rockoff
Over the years I have gotten hives, usually during very stressful times in my life. Once I got them after a prescription and they would not go away. The severity of the hives fluctuated for over 5 weeks until I went to the health food store. They suggested that I take milk thistle to help rejevenate and detox my liver. (By the way I am not a drinker or a drug user.) And it worked! The theory is that when the liver gets over stressed by toxins, life stresses, etc. it can not work to its best ability to help detoxify the body. That leaves the toxins to exit through another channel, one exit being your skin. I found that milk thistle also works for my excema (I also get excema with higher stress levels). When I see that my excema is coming back I take milk thistle until it clears up. It usually doesn't take very long for me.
I hope that this information helps someone. I recomend dropping by your local health food store and asking them some questions to see if this would be an appropriate treatment for you.
I think the hives started as a result of a stressful period in my life. However, I haven't been stressed for the full 7 years, just occasionally. It's like my body is stuck in some loop.
Think I'll try that milk thistle...