Rosacea

Definition

Rosacea is a chronic inflammatory skin disorder affecting the central face, characterized by transient or persistent erythema, telangiectasia, papules, pustules, and, in severe cases, phymatous changes.

Epidemiology

• Common in adults aged 30–50 years, more frequent in fair-skinned individuals.
• Female predominance, though males often develop more severe phymatous changes.
• Estimated prevalence: 1–10% of the adult population worldwide.
• Can coexist with ocular manifestations in up to 50% of cases.
• Genetic and environmental factors contribute to susceptibility.

Etiology

• Exact cause unknown; multifactorial: vascular dysregulation, immune system dysfunction, microbial factors (Demodex mites, Helicobacter pylori), UV exposure, and genetic predisposition.
• Triggers: sunlight, hot beverages, alcohol, spicy foods, stress, extreme temperatures, certain medications (vasodilators).
• Inflammatory pathways involve innate immune activation, vascular hyperreactivity, and abnormal neurovascular signaling.

Pathophysiology

• Dysregulation of cutaneous vasculature leads to flushing and persistent erythema.
• Innate immune system overactivity contributes to papules and pustules.
• Demodex mites may induce inflammation via follicular colonization.
• Chronic inflammation results in telangiectasia, skin thickening, and phymatous changes (especially rhinophyma).
• Ocular rosacea: inflammation affects eyelids, conjunctiva, and cornea.