Rosacea Subtypes: Neurovascular Reactivity, Demodex Etiology & Anti-Inflammatory Protocols

1. Etiology & Pathogenic Mechanisms

Rosacea is a chronic relapsing neurovascular disorder affecting primarily central facial areas (cheeks, nose, forehead, chin). Key pathogenic factors include innate immune dysregulation characterized by elevated cathelicidin antimicrobial peptide LL-37, heightened neurovascular reactivity, and microscopic overgrowth of Demodex folliculorum mites inside sebaceous infundibula.

2. The Four Primary Clinical Subtypes

• Subtype 1: Erythematotelangiectatic (ETR): Persistent central facial erythema with transient flushing, stinging, and visible fine telangiectasias.
• Subtype 2: Papulopustular (PPR): Persistent centrofacial redness with crops of non-follicular dome-shaped papules and pustules (notably devoid of comedones).
• Subtype 3: Phymatous: Severe sebaceous hyperplasia and tissue hypertrophy, most commonly affecting the nose (rhinophyma).
• Subtype 4: Ocular: Blepharitis, conjunctivitis, photophobia, foreign-body sensation, and meibomian gland dysfunction.

3. Modern Therapeutic Approaches

First-line interventions include Topical Ivermectin (1%), Azelaic Acid (15%), and subantimicrobial anti-inflammatory Doxycycline (40mg modified release daily), combined with strict UV avoidance and Pulsed Dye Laser (PDL) for telangiectasia coagulation.