What causes dermatitis?
Allergic reactions are genetically determined, and different substances cause contact dermatitis to develop in different people. A reaction to resin produced by poison ivy, poison oak, or poison sumac is the most common source of symptoms. Flowers, herbs, and vegetables can also affect the skin of some people. Burns and sunburn increase the risk of dermatitis developing, and chemical irritants that can cause the condition include: chlorine, cleansers, detergents and soaps, fabric softeners, glues used on artificial nails, perfumes, topical medications. The 3 main types of dermatitis -- atopic, contact
allergy and contact irritant -- have different causes. While not everyone agrees about the causes of atopic dermatitis, there is general agreement that it is a genetic disorder that is influenced by environmental factors. The causes and processes involved in contact dermatitis (whether allergic or irritant) are much clearer, although little is known about what makes people susceptible to allergic dermatitis.
Atopic dermatitis can be caused by allergies, asthma, or stress, and there seems to be a genetic predisposition for atopic conditions. It is sometimes caused by an allergy to nickel in jewelry. Children are more likely to develop this disorder if one or both parents have had it or have had allergic conditions like asthma or hay fever. While some people outgrow skin symptoms, approximately three-fourths of children with atopic dermatitis go on to develop hay fever or asthma. Environmental factors can bring on symptoms of atopic dermatitis at any time in individuals who have inherited the atopic disease trait. Atopic dermatitis is also associated with malfunction of the body's immune system: the system that recognizes and helps fight bacteria and viruses that invade the body. Scientists have found that people with atopic dermatitis have a low level of a cytokine (a protein) that is essential to the healthy function of the body's immune system and a high level of other cytokines that lead to allergic reactions. The immune system can become misguided and create inflammation in the skin even in the absence of a major infection. This can be viewed as a form of autoimmunity, where a body reacts against its own tissues.
Allergic contact dermatitis occurs when a highly reactive chemical substance comes into direct contact with the skin. The skin reaction, which can occur days after the initial exposure, occurs predominantly at the site of contact. Only minute quantities of the substance are needed to cause the reaction. Irritant contact dermatitis can potentially occur in anyone. The skin erupts when it encounters certain irritants, such as chemicals that directly damage the superficial layer of the skin. The damage occurs more readily in people with constantly wet hands. Common skin irritants are soaps and detergents, disinfectants and cleaning chemicals, shampoos, dyes, foodstuffs and cutting oils. As a consequence, irritant contact dermatitis is often job-related; hairdressers, cooks and caterers, dish-washers, machine-tool operators, nurses and homemakers are all at risk.
The cause of nummular dermatitis is not known, but it usually occurs in cold weather and is most common in people who have dry skin. Hot weather and stress can aggravate this condition, as can the following: allergies, fabric softeners, soaps and detergents, wool clothing, bathing more than once a day.
Seborrheic dermatitis (for which there may also be a genetic predisposition) is usually caused by overproduction of the oil glands. In adults it can be associated with diabetes mellitus or gold allergy. In infants and adults it may be caused by a biotin deficiency.
More information on dermatitis
What is dermatitis? - Dermatitis, also known as eczema, is a skin irritation characterized by red, flaky skin, sometimes with cracks or tiny blisters.
Types of dermatitis - There are several different types of dermatitis and these have different causes. The most common ones are related to allergies.
Contact dermatitis - Contact dermatitis is a dermatitis which is caused by something in the outside world which comes into contact with the skin.
Atopic dermatitis - Atopic dermatitis is a chronic, itchy skin condition that is very common in children but may occur at any age. It is also known as eczema and atopic eczema.
Seborrheic dermatitis - Seborrheic dermatitis is a common inflammatory condition of the skin. Seborrheic dermatitis is a chronic, recurring scaly rash involving the face, ears, eyebrows, scalp, and the chest.
Nummular dermatitis - Nummular dermatitis (nummular eczematous dermatitis or nummular eczema) affects the hands, arms, legs, and buttocks of men and women older than 55 years of age.
Causes of dermatitis - Each type of dermatitis has different causes. Atopic dermatitis is caused by allergies, asthma. Seborrheic dermatitis is caused by overproduction of the oil glands.
Treatments of dermatitis - Dermatitis is often treated with prescribed cortisone creams and lotions. Treating contact dermatitis begins with eliminating or avoiding the source of irritation.
Prevention of dermatitis - The most effective method of dealing with any type of dermatitis risk is through prevention. Contact dermatitis can be prevented by avoiding the source of irritation.