Infestation with Demodex mites was significantly more common in patients with rosacea compared with healthy controls, based on data from a meta-analysis of 1,513 adults with rosacea. The findings were published in the September issue of the Journal of the American Academy of Dermatology.

The cause of rosacea remains unclear and differs within subgroups, but previous studies have suggested an association between rosacea and the presence of Demodex mites, wrote Yin-Shuo Chang, MD, and Yu-Chen Huang, MD, both of Taipei Medical University, Taiwan ( J Am Acad Dermatol. 2017; 77[3]:441-7 ).

The researchers reviewed data from 23 case-control studies including 1,513 adults with rosacea. Overall, rosacea patients were 9 times more likely to experience Demodex mite infestations than healthy controls (odds ratio, 9.039) and the infestations were significantly denser in rosacea patients compared with controls. The density of the mites was significantly higher than controls for patients with either erythematotelangiectatic rosacea (standardized mean difference 2.686 or papulopustular rosacea (standardized mean difference, 2.804).

The findings were limited by several factors such as the variables in design among the studies in the analysis, and the inability of a meta-analysis to show a causal relationship, the researchers noted. However, the association between rosacea and the high prevalence of Dermodex mites “suggests that mites may play a pathogenic role in this disease,” they said.

The researchers had no financial conflicts to disclose.

Find the full study online here: