What is not obvious is that there is more than one form of scabies. One is the more regular form that usually shows up as red dots around finger webbing and other places. Another is the animal version which many fewer people get, or at least most people don't ever have a reaction to it or develop immunity after a short time or something where it doesn't affect them anyway. It is possible to pick the 2nd kind up from infected animals. There may be other forms of scabies too and differing strains of each.

Treatment for the animal kind is tougher since it since it seems more resistant and also since it doesn't seem to die off as easily when sitting around on clothes, couches, bed sheets, etc. Try washing EVERYTHING with a little bleach and at the same time taking a bath with hydrogen peroxide added. 2 or 3 bottles (~1 to 2 litres) of 30 volume (I think about 9% hydrogen peroxide content, the kind used for dying hair) in a regular sized bath is plenty. It will not dye your hair at this greatly lowered concentration, but it seems to kill the scabies, at least the ones that are on the surface. Then repeat the waashing/bathing process for 4-5 days (yes, a lot of hassle, but the scabies burrow and live under the skin for a number of days). This should do it, but make sure to vacuum up couches and rugs to clear any stragglers. Feather pillows seem to be the worst culprits of all, so either plastic wrap infected ones or perhaps toss them out.

If the infection is not treated, there can be a secondary allergic reaction to substances the mites dump out, which makes it more confusing to diagnose. 

Hope that helps.