The skin barrier is the outermost layer of the skin, composed of tightly packed skin cells and essential lipids such as ceramides, cholesterol, and fatty acids. Its primary role is to retain moisture while protecting the skin from external irritants and environmental stressors.

When this barrier becomes weakened or disrupted, moisture is lost more rapidly and the skin becomes increasingly reactive. This can present as dryness, tightness, redness, flaking, sensitivity, breakouts, and an uneven or rough texture.

Barrier impairment usually results from a combination of external stressors and internal factors.

External factors

These are influences that come into direct contact with the skin or affect it from the outside:

• Harsh or inappropriate skincare
  Alkaline or stripping cleansers, harsh soaps, and detergents can disrupt the skin’s natural acid mantle.
  Over-exfoliation — both physical scrubs and strong chemical exfoliants — can damage the barrier when used too frequently.
  Excessive or incorrect use of potent actives such as high-strength retinoids, acids, or benzoyl peroxide can overwhelm the skin.
  
• Cleansing and water exposure
  Long, hot showers or frequent washing can strip away protective lipids.
  Over-cleansing or aggressive scrubbing further compromises barrier integrity.
  
• Climate and environmental exposure
  Extreme temperatures, low or fluctuating humidity, air conditioning, and heating can increase moisture loss.
  UV exposure without adequate sun protection directly damages barrier lipids and structural proteins.
  Airborne pollutants and irritants can trigger inflammation and barrier disruption.
  

Internal factors

These relate to the skin’s inherent characteristics and overall physiological health:

• Underlying skin conditions
  Conditions such as eczema, psoriasis, rosacea, and acne are associated with inherent barrier weakness.
  
• Genetics and ageing
  Some individuals are genetically predisposed to reduced barrier function.
  With age, the skin naturally produces fewer lipids and ceramides, reducing its ability to retain moisture.
  
• Nutrition, hydration, and lifestyle
  Diets low in essential fatty acids and antioxidants can impair barrier health.
  Dehydration, chronic stress, and insufficient sleep can disrupt normal skin repair processes.
  
• Medications
  Certain medications, including topical or systemic steroids, can affect barrier function when used long term.
  

A weakened skin barrier is not uncommon and can occur at any age or skin type. The cornerstone of improvement is restoring hydration, replenishing lipids, and minimising further irritation to allow the skin to recover its protective function.