While the classification and grading of rosacea is well-established,
6 there is no agreement of the etiological agent(s) responsible for this condition nor its pathogenesis.
7 Factors such as alteration in the innate immune response, vascular changes in the skin, and the presence of a reactive oxygen species within the skin have been suggested to play a role in the induction and persistence of the condition.
2,7 Patients affected with rosacea display a higher density of facial mites,
Demodex folliculorum, than unaffected controls,
8–11 although the significance of this observation has never been explained. A bacterium (
Bacillus oleronius ) isolated from a
Demodex folliculorum mite from a patient with papulopustular rosacea produced proteins that induced an inflammatory immune response in 72% of rosacea patients but only 29% of controls (
P = 0.01).
12 The bacterium was previously isolated from the digestive tract of a termite where it may facilitate digestion.
13 A strong correlation has been established between ocular
Demodex inflammation and serum reactivity to these bacterial proteins in patients with ocular rosacea.
14 In addition, eye lid margin inflammation (
P = 0.040) and facial rosacea (
P = 0.009) were found to correlate with reactivity to these proteins.
14 These two studies
12,14 suggest a possible role for bacterial proteins in the etiology of rosacea; and the objective of the work presented here was to examine how these proteins might produce some of the pathologies associated with ocular rosacea, especially alterations to the corneal surface.