What is contact dermatitis?
Contact dermatitis is a dermatitis which is caused by something in the outside world which comes into contact with the skin. The offending substance may come into direct contact with the skin or sometimes is carried in the air. If all further contact with this substance is avoided the dermatitis should get better. Contact dermatitis is inflammation of the skin that results
from contact of an external substance with the skin. This can occur through one of two mechanisms: irritant or allergic.
Irritant contact dermatitis is a very common skin problem which affects many people at some stage of their life. It is caused by contact with substances which damage the outer layers of the skin and typically affects the hands. One of the commonest situations giving rise to irritant contact dermatitis is repeated contact with mildly irritant substances such as water and detergents (washing-up liquid, soaps, etc.). Other irritant substances include solvents, e.g.: petrol, cleaning chemicals, oils and metalworking fluids used in industry. The skin problem often starts as chapping, soreness and redness and if untreated leads to a stubborn dermatitis. Once damaged, the skin is no longer a barrier against the outside world and can easily be irritated further. This sets up a vicious circle which can be difficult to break.
People doing certain kinds of work are more at risk of getting irritant contact dermatitis than others. This includes jobs where the hands are frequently wet such as hairdressing, catering, cleaning, housework and nursing. Irritant contact dermatitis may affect people of all ages but is commonest in adults during their working years. People who have or have had bad atopic eczema are more vulnerable to irritant contact dermatitis, as their skin is less resilient to damage by irritant substances.
Allergic contact dermatitis is less common than irritant contact dermatitis. It happens because the body's immune system reacts against a specific substance or 'allergen' which has previously come into contact with the skin. People are not born with this type of allergy, but develop it during life, usually in adulthood. Allergic contact dermatitis usually affects only a minority of people who come into contact with the allergen. What makes an allergy develop at a certain time is unknown, and why one person gets affected while others don't is also unclear. The commonest cause of allergic contact dermatitis in women is nickel, which is found in metallic jewellery. About one in ten women have this type of allergy and typically develop itchy sore red patches under inexpensive earrings after wearing them. Other things that commonly cause allergic contact dermatitis include perfumes, rubber additives, leather additives and preservatives in creams and cosmetics. Allergies can also develop to medicated creams and ointments and sunscreens.
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.