I took my puppy to the vet and was told he had sarcoptic mange. Could it be misdiagnosed?

The vet said at first he had demodex. After a skin scrape she said it was sarcoptic. However my other dogs are showing no signs and neither are myself, children,or husband. Is it possible she was wrong? The puppy is not loosing hair and is a bit itchy, but I bathed all dogs in lime sulfur solution which may have dried out their skin. If it is sarcoptic how can I get it off my furniture and carpet. *Note* I have suede furniture. Also how many treatments will it take to rid him of this. I contacted the breeder and her vet and all other puppies tested negative as well as mother and my dogs as well. He has had the dip and Revolution. Thanks for all help as I have never dealt with this. Oh, he is a Shar Pei and is prone to sensitive skin as well and 10 weeks old. Thanks!
I would like to thank everyone for their helpful info. My other dogs have tested positive and I had a skin scrape today (neg for scabies), but positive for dog allergy. We are working on it and I have put them on the dip (as the vet ordered previously) and Ivermectin. Along with antibiotic for my chi as her white blood cell count is up. Once again THANKS TO ALL for the help:)

If the vet said it was sarcoptic after a skin scrape, then yes, it is most definitely sarcoptic mange. He found the mites with the scrape.

This is actually better, as it’s easily treated. Demodex is not easily treated at all,

Typical treatment for sarcoptic mange is a series of ivermectin treatments, either orally or by injection, usually over the course of 3 -6 weeks. It’s very effective.

When my dog had this (she came home from the rescue with it) we did ivermectin injections and I was told to get a spray from the pet store to treat my house and car, and to keep her away from other dogs during the treatment phase. We were also told to use Benadryl for the itching early on.

Skin scrapes only find the mites about half the time, so negative skin scrapes on the other dogs don’t mean they don’t have it. If any of them seem unusually itchy, they should also be treated. Often, sarcoptic mange is diagnosed by treating it–if the treatment works, the diagnosis is confirmed. You were lucky the scrape found the mites on your dog.

Here’s a good link on it: http://www.marvistavet.com/html/body_sarcoptic_mange.html