Rosacea is a chronic, inflammatory skin disorder that commonly affects middle-aged people of Celtic extraction. Currently, it affects 13% of the Irish population. Patients with rosacea frequently complain of dry, sensitive skin, suggesting an abnormality of their skin barrier function. The cause of this complex disease is incompletely understood.
A possible aetiological agent is the ubiquitous Demodex mite that resides within the sebaceous follicles in the face. No visible reaction occurs when mites are present in normal numbers. However, numbers of facial mites are increased in rosacea patients. Rosacea responds to antibiotic treatment but their mode of action is unknown.