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SUMMARY POINTS
What’s new
The potential role of probiotics in rosacea given the innate/adaptive immunity dysregulation and the contribution of commensal and pathogenic bacteria.
Transient receptor potential channels, vanilloid (TRPV) and ankyrin (TRPA), may contribute to the role of flushing and burning in rosacea.
Zonulin, a human protein that regulates intestinal permeability, is significantly higher in patients with rosacea.
Topical minocycline foam (Zilxi) has recently received FDA approval for the treatment of rosacea.
What’s important
Treatment of rosacea focuses on patient education, skincare, and pharmacologic/procedural interventions.
Distinguishing rosacea from other conditions and initiation of early treatment when a patient reports flushing and burning.
Treatment of rosacea involves addressing both background facial redness and inflammatory lesions.
What We Don’t Know
The pathogenesis of rosacea has yet to be fully elucidated and it is unclear whether the four rosacea subtypes are truly variants of the same condition.
The mechanism by which TLR2 is activated by Demodex mites.
The potential virulence factors of S. epidermidis in patients with rosacea.
What’s coming
The use of cromolyn, a mast cell stabilizer, in patients with rosacea.
The use of protease serine inhibitors to prevent the formation of the abnormal cathelicidin (LL-37) in patients with rosacea.
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Rosacea is a well-recognized, chronic, cutaneous condition presenting as central facial erythema, telangiectasia, papules, and pustules. A Swedish study demonstrated a prevalence of approximately 10% in the general population.1 In the United States, it is believed that there are 13 million people affected by rosacea. It is usually diagnosed between the ages of 30 and 50 years, and although both genders are affected, it is more common in women. However, more men experience phymatous changes than women. Rosacea is also more prevalent in fair-skinned than dark-skinned individuals. Sun damage, a propensity to facial flushing, and genetic predisposition are risk factors for developing rosacea.
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While the precise cause of rosacea remains unknown, genetic factors, immune system overactivity, environmental and internal triggers, and abnormal vascular response all play a role. No single causative gene has been identified through genomic studies in rosacea patients.2 However, three human leukocyte antigens (HLA-DRB1*03:01, HLA-DQB1*02:01, and HLA-DQA1*05:01) have been identified in rosacea as well as Type 1 diabetes, multiple sclerosis, rheumatoid arthritis, and celiac disease. This raises the question of a possible association with autoimmune diseases.3
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Environmental factors including ultraviolet light, heat, alcohol, hot beverages, and spicy food are all known triggers for rosacea flares.2 They are thought to induce abnormal vascular responses and flushing, along with the production of pro-inflammatory cytokines. UV radiation is known to cause exaggerated expression of MMPs, collagen denaturation, production of fibroblast growth factor 2 and vascular endothelial growth factor 2, and reactive oxygen species (ROS).2
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Overactivity of the innate immune system has been shown to be directly involved in the development of rosacea. In 2007, Gallo and colleagues observed that ...