A recently published study sought to find scientific rationale for the dual anti-inflammatory and anti-parasitic mode of action of topical ivermectin 1% cream (Soolantra) in patients with rosacea.

In a monocentric pilot study, 20 Caucasian patients with moderate to severe rosacea, as assessed by investigator global assessment (IGA score ≥ 3) and a demodex density ≥ 15/cm², were treated with topical ivermectin 1% cream once daily for ≥12 weeks. The density of Demodex mites was assessed with skin surface biopsies. Expression of inflammatory and immune markers were evaluated with RT-PCR and by immunofluorescence staining.

The study found the mean density of mites was significantly decreased at week 6 and week 12. The results showed that the gene expression levels of IL-8, LL-37, HBD3, TLR4 and TNF-α were downregulated at both time points. Reductions in gene expression were significant for LL-37, HBD3 and TNF-α at both follow up time points and at week 12 for TLR4. Reduced LL-37 and IL-8 expression was confirmed on the protein level by immunofluorescence staining. All study patients improved clinically, and 16 of the 20 patients reached therapeutic success (IGA score ≤ 1).

The study authors concluded, “Topical ivermectin 1% cream acts by a dual, anti-inflammatory and anti-parasitic mode of action against rosacea by killing Demodex spp. in vivo, in addition to significantly improving clinical signs and symptoms in the skin.”

— J Eur Acad Dermatol Venereol. 2017 Jun 27.