Eczema

Despite a known genetic cause, the exact mechanism and factors involved in the formation of eczema are yet to be fully understood. What we do know is that there is a dual problem of skin barrier dysfunction (compromised skin barrier allowing increased penetration of environmental irritants and allergens through the upper layers of the skin) and an excessive immune reaction (causing release of inflammatory mediators in the skin resulting in redness, itch and swelling). This combination acts as a vicious cycle resulting in further breakdown of the skin barrier and worsening of the eczema. The severe itch makes scratching very difficult to resist, further contributing to the broken skin barrier and setting up an itch-scratch-cycle typical in eczema.

There are many other less common forms of eczema or dermatitis.

These include:

• Irritant dermatitis: skin barrier breakdown due to physical or chemical irritation on the skin eg excessive hand washing
• Allergic contact dermatitis: delayed hypersensitivity reaction to chemical in direct contact with the skin eg nickel allergy (costume jewellery), allergy to components of creams, hair dyes etc
• Asteatotic eczema: skin barrier disruption due to dryness and loss of integrity of the skin typically seen in older age

Common types of eczema:

• Irritant Contact Dermatitis: Results from repeated exposure to irritants like soaps or solvents, leading to skin barrier breakdown.​
• Allergic Contact Dermatitis: An immune reaction to allergens such as nickel, certain cosmetics, or hair dyes.​
• Asteatotic Eczema: Often seen in older adults, this type arises from extremely dry skin, leading to cracking and inflammation.