Rosacea

Rosacea is a chronic skin disease characterized by recurring redness, visible blood vessels, and inflammation, primarily affecting the forehead, nose, cheeks, and chin.

Overview

Rosacea is a long-lasting (chronic) skin disease that affects the face. The signs and symptoms vary, often coming and going or changing over time. There are three main types of rosacea, categorized by their primary characteristics:

• Erythematotelangiectatic rosacea: Causes skin redness, warmth (flushing), and visible clusters of blood vessels (telangiectasia).
• Papulopustular rosacea: Causes skin redness, swelling, and pus-filled bumps called pustules.
• Phymatous rosacea: Characterized by thickened skin on the face and an enlarged, bulbous nose (rhinophyma).

Affected individuals may experience itching, stinging, or burning sensations. The disorder often affects the eyes (ocular rosacea), causing inflammation of the eyelids and eyes, which can lead to dryness, redness, irritation, and potential vision impairment.

Frequency

Rosacea is a common condition, with prevalence estimates ranging from less than 1 percent to more than 20 percent of the population. It is reported most frequently in fair-skinned individuals, particularly those of western European ancestry. It is diagnosed most often in early to mid-adulthood, and women appear to be affected more often than men.

Causes & Risk Factors

The causes of rosacea are complex and involve a combination of genetic and environmental factors. Research suggests the condition is associated with abnormalities in the vascular system and the immune system, as well as a disruption of the skin's protective barrier.

Genetic Factors

Several genes are thought to play a role in rosacea, including:

• HLA complex genes: Variations in genes such as HLA-DQA1, HLA-DQB1, and HLA-DRB1 help the immune system distinguish the body's proteins from foreign invaders; certain variations likely contribute to abnormal inflammation.
• Glutathione S-transferases (GSTs): Genes such as GSTM1 and GSTT1 produce proteins that protect cells from oxidative stress. Variants in these genes may reduce this protection, leading to cell damage and inflammation.

Environmental Factors

Environmental triggers can increase the risk of developing rosacea or worsen symptoms:

• Exposure to ultraviolet (UV) radiation from the sun.
• Overgrowth of microorganisms on facial skin, such as the mite Demodex folliculorum.
• Heat exposure, spicy food, cigarette smoking, and alcohol, which cause blood vessels to dilate.

Inheritance

Rosacea does not have a straightforward pattern of inheritance. People with the condition are four times more likely to have a family history of the disorder, suggesting that both shared genetic factors and shared environmental influences play a role.