As I am one of the firsts that treated the disease with ivermectin (including Soolantra), you might have read already that I was fully clear after one month. After two months of taking Soolantra I stopped.
The bad news are that after around four months not taking Soolantra anymore (middle of Dec 2015) I had a new lesion again. Therefore, I went to my doctor the next day and we agreed that I take Soolantra continuously from now on. Since then, I am lesion free, again.
I think the number of demodex grew again after I stopped using the cream anymore. So unfortunately, the mites can come back even after I rather "small" time.
Feel free to share your long term experiences. In contrast to me, firstman reported at the other forum that he did not experiences any come back in the first months, so the experiences might be different for different people.