If it has returned, then go ahead and restart another course of clindamycin-IPA if you can. However, this time, also add an oral dose of Bacillus Subtilis probiotic to your daily routine. this has been shown to significantly diminish staph growth and colonization in your body. Here is a link to one of the vendors you can get it from on Amazon:
But Also, I recommend that if you haven't yet, get your scalp swabbed to make sure it is indeed staph that is causing the follicultitis (which it most likely is) to ensure you are using the proper antibiotics for this protocol.
Is your disease confirmed to be caused by Staph? If it is (and it most likely is), try another course of this therapy. However, this time, also add an oral dose of Bacillus subtilis probiotic to inhibit staph growth and colonization in your body. I have attached a link to it on Amazon. But you can buy it from other vendors as well.
First, I'm so sorry to hear about your wife's struggle with this awful disease. I know how devastating this can be, especially for a woman. But I am happy to hear this treatment has at least been doing her some good. Nonetheless, this is a very curious case, especially due to the ambiguity of the disease-causing microorganism.
Even though the cause remains officially inconclusive, it is best to assume that staph is likely the main culprit, for now, considering that this protocol has been working for her, and that Staph is almost always the main culprit for chronic scalp folliculitis.
Therefore, I will suggest looking into adding an extra weapon to your arsenal, if you are able to do so: Bacillus subtilis probiotic. There is a promising phase II clinical trial published 10 days ago which shows that consuming this probiotic (A.K.A Healthy bacteria) significantly reduces Staph growth and colonization throughout the body.
Here is the link to the study.
And here is a link to one of the few vendors you can buy it from on Amazon.
Hope this helps, and keep us updated on the progress if you could.