• A characteristic feature is flushing that may have a number of triggers.
• It is a chronic acneform disorder of the facial pilosebaceous glands with an increased reactivity of capillaries to heat, causing flushing and eventually telangiectasia.
• Rhinophyma is an enlarged nose associated with rosacea which occurs almost exclusively in men.
• The actual aetiology of the disease is unknown.
• Recent molecular studies propose that an altered innate immune response is involved in the pathogenesis of the rosacea disease.
• Histologically, dilated lymphatics and blood vessels, as well as perivascular infiltration of CD4+ helper T cells, macrophages and mast cells can be readily seen.
• Medications which can cause a recurrence include amiodarone, topical steroids, nasal steroids and vitamins B6 and B12.
• Recent research has highlighted the importance of skin-environmental interactions. The impairment of the skin barrier function and the activation of the innate immune defences are major and connected pathways contributing to an ongoing inflammatory response in the affected skinThis becomes modulated by endogenous factors like neurovascular, drugs, and also by psychological issues.
• There has been a long debate on the role of Demodex mites (which usually inhabit human hair follicles) in rosacea. The prevalence of Demodex mites in rosacea patients has been estimated to be as high as 60% (clinically) and 80% (in skin biopsies).However, increased Demodex density in rosacea is considered to be an aggravating factor but not a causative one

Signs
The disease tends to be progressive but that does not mean that everyone will develop all features.
• The skin is not greasy as in acne and may be rather dry.
• Erythema and telangiectasias over the forehead and cheeks are variable.
• Although the usual areas affected are the nose, cheeks and forehead, other areas, such as the neck, chest and ears, can become involved.
• Sebaceous glands are prominent.
• The nose may be enlarged and distorted by rhinophyma.
• There may be peri-orbital oedema.
Flushing
Causes of flushing are many and include:
• Heat or changes in temperature.
• Alcohol.
• Caffeine.
• Spicy foods.
• Stress or embarrassment.
• Sun or wind.
• Medication that causes vasodilatation.
Treatment of rosacea depends on the severity and type of rosacea present. Although rosacea's impact on physical health is limited, it has profound effects on a person's psychological well-being.[3]Therefore, treating rosacea can greatly affect a person's quality of life. Although there are numerous treatments available, none of these is completely curative.

A Cochrane review of treatments for rosacea has summarised that there is high-quality evidence to support the effectiveness of topical azelaic acid, topical ivermectin, brimonidine, doxycycline and isotretinoin for rosacea. Moderate-quality evidence is available for topical metronidazole and oral tetracycline. There is low-quality evidence for low-dose minocycline, laser and intense pulsed light therapy and ciclosporin ophthalmic emulsion for ocular rosacea.