https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3614089
The above was for acne but it says about Isotretinoin:
"Treatment of patients with isotretinoin significantly decreased monocyte TLR-2 expression and subsequent inflammatory cytokine response.. This effect was sustained six months following cessation of therapy, indicating that TLR-2 modulation may be involved in the durable therapeutic response to isotretinoin.
The modulation of TLR-2 expression on monocytes has important implications in other inflammatory disorders characterized by TLR-2 dysregulation."
If you can find a dose low enough that doesn't aggravate redness or flushing it can help down-regulate and normalize TLR-2 expression (TLR-2 is indicated in the pathogenesis or Rosacea). That might be how it helped you.