Various rashes are common indicators of atopic dermatitis (eczema), but the rash is generally caused by scratching and not by the condition itself. In atopic dermatitis, the skin is not as effective a barrier as it should be. A protein in the skin called filaggrin is part of the network of proteins that holds the skin together. When this protein does not work correctly, the skin becomes dry and easily irritated. People with atopic dermatitis also tend to have allergies to ordinary substances, such as milk and eggs.
The weakness of the skin barrier can also lead to serious infections from germs the body normally fights off or resists effectively. Staph (a bacterium that lives on the skin) can penetrate the skin barrier of a person with atopic dermatitis, resulting in an infection not seen in most people. Infections of human papilloma virus (HPV) or herpes simplex viruses can be more serious in skin compromised by atopic dermatitis than in the skin of most people. Having atopic dermatitis is also a risk factor for asthma.
Atopic dermatitis begins more often in children than in adults. Even infants can begin to show symptoms of the condition. It seems to result partly from genetics and partly from irritants or allergens in the environment. Many patients with atopic dermatitis have dry skin, and research studies suggest that the barrier of their skin does not work as well, which makes skin more susceptible to irritants. Some common irritants are wool and synthetic clothing, fabric softener and other fragrances. Regardless of what triggers atopic dermatitis, it is a chronic condition that should be managed.
Atopic dermatitis (eczema) can be very challenging to treat effectively. It is an autoimmune disorder, which means that the immune system has become sensitized to the skin and is attacking it.