What is Atopic Dermatitis?
Atopic dermatitis, a particular type of eczema, is the most prevalent long-term skin condition causing inflammation. This chronic condition often begins in early childhood and is characterized by dry skin, eczema-like sores, and thickened, rough skin. It is thought to be related to other conditions associated with a type of antibody called IgE, such as allergies that affect the nose, asthma, and food allergies. Atopic dermatitis can considerably impact a person’s quality of life, and it seems that the number of people affected by this condition has been increasing over recent years.
What Causes Atopic Dermatitis?
Atopic dermatitis, or eczema, is caused by a number of things, including both genetic factors and environmental influences. These lead to abnormalities in both the skin and the immune system. Atopic dermatitis comes as part of a set of conditions often found together, known as the “atopic triad”. This includes eczema, hay fever (allergic rhinoconjunctivitis), and asthma, which may all start at the same time or one after the other, in a progression known as the “atopic march”.
People with the atopic triad have defects in their skin, nasal passageways, and airways which cause their symptoms. When one parent has any of these conditions, there’s more than a 50% chance their child will develop symptoms too. If both parents have an atopic condition, the likelihood goes up to 80%. Certain genetic changes specifically can make people more prone to atopic dermatitis – and one of these changes affects a skin protein called filaggrin, which helps skin stay moist. Up to 30% of people with atopic dermatitis have these changes, which can also lead to dry, scaly skin (ichthyosis vulgaris), hay fever, and tiny bumps on the skin called keratosis pilaris.
Food allergies can also trigger or worsen atopic dermatitis in 10% to 30% of patients. Eggs, milk, peanuts, soy, and wheat cause 90% of these reactions or flare-ups. Some recent studies have also found a connection between smoking and developing atopic dermatitis in adulthood.
Risk Factors and Frequency for Atopic Dermatitis
Atopic dermatitis, a skin condition, is found in about 10% to 30% of children and 2% to 10% of adults in developed countries. There has been a two to three-fold increase in its prevalence in the past few decades. The incidence of this condition is higher in areas with higher latitudes, which is possibly due to less sun exposure and dry weather. There are three subsets of atopic dermatitis based on when the condition begins:
- Early-onset atopic dermatitis (birth to 2 years old): This is the most common form, with about 60% of cases starting by a child’s first birthday. Roughly 60% of these cases resolve by the time the child turns 12.
- Late-onset atopic dermatitis: This variant actually starts after puberty.
- Senile onset atopic dermatitis: This is a rare version that begins in people over 60 years old.
Signs and Symptoms of Atopic Dermatitis
When a doctor is assessing a patient potentially suffering from atopic dermatitis, certain factors are considered. These include:
- When the skin changes first appeared and their location
- How severe the itchiness is (for example, if it’s keeping the patient awake at night)
- If the patient or family members have a history of the atopic triad (eczema, hay fever, and asthma)
- If the patient has been in contact with substances that cause allergies
- Whether certain triggers are present, such as dust mites, pet hair, hot showers, soaps, fragrances, food sensitivities, or synthetic fabrics like polyester
The typical signs a doctor looks for during a physical examination depend on the patient’s age. Infants, for instance, may have raised, swollen spots or areas on their scalp, face, and outer arms and legs. These may be topped with fluid-filled sacs or a crust. Usually, infants’ diaper areas are not affected by eczema, but they can get diaper rash from other causes like yeast or seborrheic dermatitis.
Children with eczema usually have drier patches on the inner folds of their elbows or behind their knees. Adults on the other hand, often develop thickened, lichenified (skin with a leathery or scaly texture and increased lines) areas, particularly on their hands. Also, the skin changes can be categorized as:
- Acute (swollen, red spots or areas and/or blisters/crusting)
- Subacute (redness, flaky skin, varying degrees of crustiness)
- Chronic (thick areas with increased skin lines and scales)
Testing for Atopic Dermatitis
Atopic dermatitis, commonly known as eczema, is usually diagnosed by looking at the pattern and location of skin rashes in different age groups. Other related symptoms, such as small bumps on the skin (also known as keratosis pilaris), can also help doctors make a diagnosis. If a skin biopsy is done, it will show patterns typical of eczema.
In children with eczema that doesn’t respond well to treatment, doctors can perform specific tests to check for antibodies related to allergies. These tests can reveal the presence of antibodies known as immunoglobulin E (IgE), which react to specific substances that a person might be allergic to. However, it’s important to note that these substances may or may not play a part in causing or worsening the person’s eczema.
Treatment Options for Atopic Dermatitis
Treatment for skin problems usually involves four main aspects: avoiding triggers, daily skin care, anti-inflammatory treatments, and other complementary methods.
Everyday skincare involves twice-daily application of moisturizers. It’s best to apply these within three minutes of stepping out of a lukewarm shower or bath to keep the skin from drying out. Ointments are quite effective but may feel greasy. Topical steroids can help manage acute flare-ups and should be applied before moisturizers to maximize their effect. While very effective, be mindful that prolonged steroid use can cause skin thinning and visible blood vessels.
More delicate areas like the arm pits, groin, and the face might require topical non-steroidal treatments like tacrolimus and pimecrolimus. Newer medicines include crisaborole, which works by blocking an enzyme called PDE-4. If topical treatments aren’t enough, other treatments may include light therapy (ultraviolet A, ultraviolet B, and narrow-band ultraviolet B), and drugs like cyclosporine, azathioprine, mycophenolate mofetil, and methotrexate.
Dupilumab, a drug that’s been recently approved by the FDA, can block the effects of certain biochemicals in the immune system and thus help manage inflammation in the skin. Complementary measures might include bathing in a tub with half a cup of bleach one or two times per week to cut down on bacteria, low-allergy diet for breastfeeding mothers, and probiotics and prebiotics for pregnant women and infants at risk. Some studies have shown these methods can cut the rate of skin problems in infants by 50% between the ages of 1 and 4.
Recently, a topical ointment called crisaborole was approved for mild to moderate cases of skin inflammation. This drug works by blocking a specific enzyme and can help improve skin symptoms.
Probiotics might also help some patients, as it is believed that their bacterial products could boost the immune system and stop the development of allergic responses. Probiotics are usually recommended for pregnant women and women who are breastfeeding.
Several studies have found that bleach baths might help relieve symptoms by reducing the risk of bacterial infection.
What else can Atopic Dermatitis be?
When a person has skin problems, the doctor might consider several possible conditions. These could include:
- Allergic contact dermatitis (an allergic reaction that causes skin inflammation)
- Lichen simplex (a chronic skin disorder causing constant itching and scratching)
- Lichen planus (an inflammatory condition that can affect the skin and mouth)
- Psoriasis (a skin disease that causes red, itchy, scaly patches)
- Scabies (a skin infestation by a tiny mite)
- Tinea (a fungal infection on various parts of the body, also known as ringworm)
- Seborrheic dermatitis (a common skin condition that mainly affects the scalp)
Doctors look into these conditions as potential causes of skin issues and use appropriate tests to make an accurate diagnosis.
What to expect with Atopic Dermatitis
Generally, many patients with atopic dermatitis (AD), a type of skin condition, see improvement over time. Yet, these patients may also suffer from allergies like hay fever and asthma, which might not improve. In many instances where AD begins in childhood, the disorder can last for decades. It’s a condition that can come and go, with flare-ups often needing medication.
Exposure to smoke, pet hair and dander, pollen, and other triggers such as certain soaps and detergents, or wool, can maintain constant symptoms and reduce overall quality of life.
Persistent and recurring itching can not only be bothersome, but it’s also cost-intensive to manage. A notable complication of AD is Kaposi varicelliform eruption, a condition associated with a primary herpes infection. This leads to blister-like sores appearing in the areas affected by eczema and they can rapidly spread to unaffected skin. Treatment with a medication called acyclovir can help reduce the severity of this complication.
People with AD also have a higher risk of skin infections caused by bacteria like Staphylococcus and Streptococcus.
Possible Complications When Diagnosed with Atopic Dermatitis
Common Conditions:
- Kaposi varicelliform eruption
- Bacterial infection
- Uriticaria
Preventing Atopic Dermatitis
It would be beneficial for patients to wear clothes made from cotton and avoid those made from wool. It’s also helpful to keep the temperature in your home cooler as this can reduce excessive sweating and uncomfortable itching. Using a humidifier can be beneficial too, as it helps to prevent your skin from drying out. Additionally, any foods that are known to bring on AD symptoms should be kept out of the diet.