The term eczema is used to describe all kinds of red, blistering, oozing, scaly, brownish, thickened, and itching skin conditions. Examples of eczema include dermatitis, allergic contact eczema, seborrheic eczema, and nummular eczema. The term atopic describes a group of allergic or associated diseases that often affect several members of a family. These families may have allergies such as hay fever and asthma but also have skin eruptions called atopic dermatitis (AD). While most people with AD have family members with similar problems, 20% may be the only one in their family bothered by this problem. AD is very common in all parts of the world. It affects about ten percent of infants and three percent of the U.S. population overall. The skin rash is very itchy and sometimes disfiguring.

Diagnosis is primarily based on the appearance of the skin and on personal and family history. The health care provider should examine the lesions to rule out other possible causes. A skin lesion biopsy may be performed, but is not always required to make the diagnosis. This disease may result in an increased eosinophil count.

Symptoms can include: intense itching, blisters (vesicle formation) with oozing and crusting, skin redness or inflammation around the blisters, and rash. In children under 2 years old, skin lesions begin on the cheeks in infants and may progress to the scalp, arms, trunk, and legs; they may also exhibit dry, leathery skin areas (lichenification), more or less pigment than their normal skin tone (normally found in the inner elbow or behind the knee). It may spread to the neck, hands, feet, eyelids, or behind the knee. Raw areas of the skin (excoriation) may arise from scratching and ear discharges or bleeding.

The condition usually improves in childhood or sometime before the age of 25. About 60% of patients have some degree of dermatitis and some suffer throughout life. When the disease starts in infancy, it's sometimes called infantile eczema. This itching, oozing, crusting condition tends to occur mainly on the face and scalp, although spots can appear elsewhere. In attempts to relieve the itching, the child may rub their head and cheeks and other affected areas with a hand, a pillow, or anything within reach. Parents should know that many babies improve before two years of age. Proper treatment can be helpful, sometimes controlling the disease until time solves the problem. One study found the longer a baby was breast-feed from a mother with eczema, the greater the risk of their developing it too.

If the disease continues or occurs beyond infancy, the skin has fewer tendencies to be red, blistering, oozing and crusting. Instead, the lesions become dry, red to brownish-gray, and the skin may be scaly and thickened. An intense, almost unbearable itching can continue, becoming severe at night. Some patients scratch at their skin until it bleeds and crusts. When this occurs, the skin may become infected.

Amongst teens and young adults the eruptions typically occur on the elbow bends and backs of the knees, ankles and wrists, and on the face, neck and upper chest. Although these are the most common sites, any body area may be affected. An itching rash as described above, along with a family history of allergies, may indicate atopic dermatitis. Proper, early and regular treatment by a dermatologist can bring relief and also may reduce the severity and duration of the disease.

The disease does not always follow the usual pattern. It can appear on the palms or backs of the hands and fingers, or on the feet, where crusting, oozing, thickened areas may last for many years.

Emotional tension can provoke and aggravate itching in patients with AD and, according to a number of studies, AD patients show higher levels of anxiety, hostility and neurosis than matched controls. Neurodermatitis is a form of atopic dermatitis characterized by a self-perpetuating scratch-itch cycle. Although symptoms increase in times of stress, physiological changes in the nerve fibers are also present.

Avoid sweating and rough-textured clothing. Wash clothing with mild soaps only and rinse thoroughly, and avoid exposure to chemical irritants and any other agent that might cause skin irritation. Local application of soothing lotions ameliorates itching (zinc oxide works well), but greasy preparations should not be used for extended periods since they block the sweat ducts. The historic use of arctium lappa and other inulin-containing herbs for eczema has scientific validity.

Hand eczema may improve by wearing white cotton gloves covered with rubber gloves to avoid contact with irritants. Hands should be patted, not rubbed dry after each washing. With all forms of eczema, bathing too frequently can dry the skin and make the problem worse. Scratching tends to worsen the problem. Cold compresses may reduce itching. A larger list of eczema types with a brief description of each can be found at the Eczema Types page.

Scientists at the University of Dundee have taken a step closer to a full understanding of eczema and related allergic diseases with the discovery that people from different ethnic backgrounds have different mutations of the gene that causes the debilitating skin disorder.

Professor Irwin McLean and his team from the College of Medicine, Dentistry and Nursing at the University of Dundee, together with Dr Alan Irvine in Dublin, have used a groundbreaking new method to examine the filaggrin gene. The team made a major breakthrough last year when they reported that defects in the filaggrin gene can cause dry skin, eczema, eczema-associated asthma and other allergies. Their continued work has now shown that within the gene there can be several faults and that eczema sufferers of different ethnic backgrounds will have different faults within the gene. Their findings will be published in Nature magazine.

They have found, so far, 15 different mutations within the gene - if you have a mutation in your gene, you have a 60 per cent chance of having eczema. If you have two mutations in your gene, you have an almost 100 per cent chance of having eczema.

Of the mutations, 5 were prevalent in the European patients examined, who were mainly from the UK and Ireland, and 9 per cent of the population were shown to carry these gene defects. There are two mutations which are the most prevalent in all European people.

There were also two mutations prevalent in the Oriental populations that were tested. Four per cent of people of Chinese descent carry this mutation, meaning it could lead to eczema in more than 50 million people in the Far East alone.

Other mutations in the gene were found in single families and so are very rare or family specific.

The filaggrin gene is one of the hardest to decipher because of its repetitive pattern, but McLean's laboratory have developed a new method which analyses the gene fully and will allow all defects to be identified.

Based on the results, it is predicted that the filaggrin gene will be found to be a major gene for these diseases in the global sense.

Eczema affects one in five children in the UK alone and is just as common in most parts of the world. In the UK and Irish populations, the Dundee and Dublin groups have shown that the filaggrin gene is involved about half of the severe, difficult-to-treat cases of eczema. [April 2007]