My son was treated for scabies two months ago , but it hasn't healed completely, why ?

Scabies: Sometimes the irritation after the scabies have been treated can be pretty significant, BUT two months is a long time and it is possible that he was re infected from the same place he got them in the first place. A repeat evaluation is necessary.

Many reasons: Could be a few reasons. First, the diagnoses could be wrong & the child doesn't have scabies. Secondly, sometimes the "bumps" associated with scabies can take months to go away. It could also be a dermatitis due to irritation of the skin by the mites. Last, the mites could be resistant to the medication used to treat them.I'd recommend having your MD reevaluated him.

See physician: if still not healed, needs to be assessed again. May be need more treatment or the diagnosis may need to be re-assessed