Atopic Dermatitis Overview

A skin condition characterized by inflammation, itching, and dryness. Primarily affects the skin's permeability barrier, immune system, and microbiome.

The outer layer of skin, responsible for protecting the body from external factors (temperature, microbes, etc.).

Lipid molecules within the Stratum Corneum, crucial for maintaining the skin's barrier function and preventing water loss.

The breakdown of the skin's barrier function, leading to increased permeability and susceptibility to irritants, allergens, and microbes.

Enzymes in the skin that break down proteins, contributing to skin barrier dysfunction, especially in AD.

The abnormal separation or detachment of corneocytes, leading to a weakened skin barrier and easier entry for irritants and allergens.

The complex system of immune cells and molecules that defend the body from infection and disease, playing a key role in AD development.

A state of imbalance within the immune system, leading to an excessive inflammatory response, a hallmark of AD.

The community of microorganisms (bacteria, fungi, viruses) that live on the skin, influencing skin health and contributing to AD development.

Changes in the composition or balance of the cutaneous microbiome, increasing susceptibility to inflammation and AD.

A common inflammatory skin condition often starting in infancy, associated with other atopic conditions like asthma and allergies.

AD is characterized by intense itching (pruritus) and a chronic, recurring course. Inflammation is the hallmark, with different presentations depending on age.

In infants, AD commonly affects the face, scalp, and extensor surfaces (backs of arms/legs). In children and adults, it shifts to flexural areas (elbows, knees).

AD can make the skin more susceptible to infections caused by bacteria like Staphylococcus aureus (S. aureus) and viruses like Herpes Simplex Virus (HSV).

The goals of treating AD include avoiding triggers, using emollients (moisturizers) regularly, and controlling inflammation both during flares and in between.

The incidence of AD peaks in infancy, with many children experiencing chronic forms of the disease.

There are different subgroups of AD based on age of onset, each with unique characteristics.

Early-onset AD, starting within the first two years of life, is the most common type. It often involves IgE antibodies (allergy markers).

Late-onset AD, starting after puberty, accounts for a significant portion of cases, but fewer patients develop allergy markers (IgE antibodies).

AD in the elderly is a distinct subtype, starting after 60 years of age. It's more common in women.

The outer layer of the skin, which acts as a barrier to protect the body from environmental factors like microbes and temperature.

A protein that helps bind keratin filaments together in the Stratum Corneum, contributing to the skin's barrier function.

A state of imbalance in the immune system, leading to excessive inflammatory responses, which are common in Atopic Dermatitis.

The community of microorganisms that live on the skin, influencing skin health and contributing to the development of Atopic Dermatitis.

The breakdown of the skin's barrier function, leading to increased permeability and susceptibility to irritants, allergens, and microbes.

Changes in the composition or balance of the cutaneous microbiome, increasing the susceptibility to inflammation and Atopic Dermatitis.

Enzymes in the skin that break down proteins. They can contribute to skin barrier dysfunction, especially in Atopic Dermatitis.

The abnormal separation or detachment of corneocytes (skin cells) in the Stratum Corneum, leading to a weakened skin barrier.

These lipids are essential for maintaining the skin's barrier function and preventing water loss. They help regulate the passage of water and other substances into and out of the skin.

Atopic Dermatitis (AD) involves a weakened skin barrier causing excessive water loss and increased entry of allergens and irritants. This occurs due to abnormalities in the lipid composition of the Stratum Corneum.

These enzymes break down proteins in the skin, contributing to problems like corneocyte detachment and a less effective skin barrier. They are often elevated in AD.

The immune system's job is to protect the body from infections and diseases. In AD, the immune system becomes overactive causing inflammation and itching, leading to the characteristic symptoms of AD.

Atopic Dermatitis has a complex relationship with the skin microbiome. This includes bacteria, fungi, and viruses. An imbalance in these microbes can contribute to AD symptoms.

The microbes present in the cutaneous microbiome represent the pathogenic and commensal homeostasis. These include bacteria (S.aureus), fungi (Malassezia) and viruses (HSV). So any changes in their environment leads to AD. All these factors lead to an easier entry for irritants, microbes and allergens. This will trigger the immune responses, which leads to release of inflammatory mediators and cytokines.

Atopic Dermatitis can affect people of all ages, but depending on the age, the location and characteristics of the skin lesions may change. Infants often have patches on the face, scalp, and trunk. Older children and adults typically experience outbreaks in flexural areas.