What is Atopic Dermatitis?
Atopic dermatitis, a specific type of eczema, is the most common long-term inflammatory skin disease. This persistent disorder often begins in infancy, showing symptoms like dry skin, eczema-like sores, and thickened, patchy skin. It’s thought to be connected to other allergy-related conditions like hay fever, asthma, and food allergies, all of which involve an immune response known as IgE. Atopic dermatitis can greatly affect a person’s quality of life and it seems that the number of people with this disorder has been growing over the last few decades.
What Causes Atopic Dermatitis?
Atopic dermatitis, or eczema, is a skin condition with complex causes, including genetics and environmental factors. These cause irregularities in the skin’s surface layer and the body’s immune system. It’s part of the ‘atopic triad’ which also includes allergic rhinoconjunctivitis (an allergic reaction causing inflammation of the nose and eyes) and asthma. These can either occur at the same time or one after the other, in what’s known as the ‘atopic march’.
People with the atopic triad have defective barriers in their skin and respiratory systems which cause their symptoms. If one parent has an atopic condition, their child has more than a 50% chance of also being affected. This risk goes up to 80% if both parents have these conditions. Genetic changes in these cases often involve the malfunction of a skin protein called filaggrin, which helps keep the skin moisturized. Up to 30% of people with atopic dermatitis have these filaggrin mutations, which can also make them vulnerable to skin conditions like ichthyosis vulgaris (dry, scaly skin), allergic rhinitis (hay fever) and keratosis pilaris (rough, bumpy skin).
Additionally, food sensitivities can trigger or worsen atopic dermatitis in about 10% to 30% of people. Most of these flare-ups, about 90%, are caused by certain foods such as eggs, milk, peanuts, soy, and wheat. Recent research also hints at a link 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. The number of people affected by this has risen two to three times over recent years. It’s more common in places where there’s less sunshine and low humidity. Depending on when someone starts showing symptoms, atopic dermatitis can be sorted into three groups:
- Early-onset atopic dermatitis (from birth to 2 years old): This is the most common type and about 60% of these cases start before a child turns 1. By the time they’re 12, 60% of them no longer show symptoms.
- Late-onset atopic dermatitis: This group starts showing symptoms after hitting puberty.
- Senile onset atopic dermatitis: This is rare and only starts in people older than 60 years old.
Signs and Symptoms of Atopic Dermatitis
When examining a patient for possible skin conditions, doctors should consider several factors found in the patient’s history:
- The time and pattern of skin lesion development
- The severity of itching, such as if it’s keeping the patient awake at night
- Any personal or family history of related conditions such as eczema, hay fever, or asthma
- Exposure to certain substances that can cause skin allergies
- Possible triggers, which could include dust mites, pet dander, hot showers, sweating, soaps, fragrances, food allergies, and synthetic fabrics like polyester
The signs a doctor looks for during a physical examination can depend on the patient’s age group. For babies, they may find swollen bumps and patches that may have small fluid-filled blisters or crusts on the scalp, face, and outer arms and legs. Babies typically don’t have these skin lesions in the diaper area, but they might have diaper rash due to other factors like a yeast infection or another skin condition.
Children with this skin condition often have less oozy patches and plaques on the inner elbows and knees. Adults, on the other hand, typically have long-term skin changes with enhanced skin markings that preferentially affect the hands. Individual lesions may also be classified into stages: acute (marked by swollen, red patches and plaques and/or blisters or crusts), subacute (redness, flaking, varying levels of crusts), or chronic (thick plaques with skin thickening and flaking).
Testing for Atopic Dermatitis
Atopic dermatitis, also known as eczema, is typically diagnosed based on the appearance and location of skin rashes, which can vary by age group. Additional symptoms, like ‘keratosis pilaris’ or ‘chicken skin’, can also help in the diagnosis. A skin biopsy test can help confirm the diagnosis by showing a pattern typical of eczema.
In children, if the condition doesn’t improve after usual treatment, doctors may recommend specific tests. These can include fluorescent enzyme immunoassays or skin prick tests to detect specific antibodies called Immunoglobulin E (IgE). These antibodies commonly react to specific allergens, potentially worsening the skin condition. However, it’s important to note that the presence of these IgE antibodies may not always directly contribute to the skin’s condition.
Treatment Options for Atopic Dermatitis
The four main aspects of treatment include staying away from triggers, daily skin care, use of anti-inflammatory medications, and other additional treatments.
Everyday skin care involves applying moisturizing creams twice daily, preferably within three minutes of a warm (not hot) bath or shower to prevent skin from drying out. Ointments are most effective at forming a barrier on the skin, but they may feel a bit greasy. Topical steroids, which should be applied before moisturizers to maximize their effect, are the go-to treatment for acute flare-ups. They should be strong enough to rapidly control a flare-up, with the possibility of reducing the frequency to every other day and twice a week for maintenance, typically over weekends, on the usual affected areas. Keep in mind that long-term use of steroids can cause thinning of the skin and tiny red spots or veins.
For delicate areas, including the underarms, groin, and face, you may need to use non-steroidal creams such as tacrolimus and pimecrolimus. There are recent treatments as well, like crisaborole, that works by blocking PDE-4. If the condition is severe and not responding to creams or ointments, other treatments could include light therapy (UVA, UVB, and narrow-band UVB), cyclosporine, azathioprine, mycophenolate mofetil, and methotrexate.
A new FDA-approved biological treatment, dupilumab, can also be considered. It’s a type of protein that blocks another protein (IL-4 receptor) that is involved in inflammatory processes in the body. Other additional treatments include bleach baths (adding 0.5 cup of bleach in a full 40-gallon tub) once or twice a week to reduce the amount of Staphylococcus aureus bacteria on the skin, sticking to a low-allergen diet during breastfeeding, and using probiotics and prebiotics during
pregnancy or in high-risk infants. This has led to a 50% decrease in the frequency of this skin condition in children aged 1 to 4 years compared to a placebo.
Another recently approved treatment for mild to moderate cases of the condition is Crisaborole topically applied ointment – this medicine improves skin symptoms by blocking a process in the body that leads to inflammation.
Lastly, some patients might find probiotics helpful as they can enhance the immune system and potentially prevent the development of an allergic response. Probiotics are particularly recommended for pregnant and breastfeeding women.
Many studies have shown that using a certain amount of bleach in baths can help to relieve symptoms by decreasing the risk of bacterial infection on the skin.
What else can Atopic Dermatitis be?
When someone exhibits symptoms like skin irritation or a rash, a doctor would have to consider several possible conditions or diseases to make an accurate diagnosis. These could include:
- Allergic contact dermatitis (a skin reaction to an allergen)
- Lichen simplex (a skin disorder resulting from continuous scratching)
- Lichen planus (a condition that can cause swelling and irritation on the skin, hair, nails or mucous membranes)
- Psoriasis (a condition that speeds up skin cell growth, leading to patches of red, scaly skin)
- Scabies (an itchy skin condition caused by a tiny burrowing mite)
- Tinea (a fungal infection of the skin, hair or nails)
- Seborrheic dermatitis (a common skin condition that mainly affects your scalp, causing scaly patches, red skin and itchy dandruff).
The doctor would then conduct necessary tests, examine the skin’s condition, and take into account the patient’s medical history, to correctly identify the cause of the skin condition.
What to expect with Atopic Dermatitis
Many people with Atopic Dermatitis (AD) see improvements over time. However, it’s important to note that those who also suffer from allergic rhinitis and asthma may not see the same improvements. AD, especially when it begins in childhood, often lasts for decades.
This condition can go through cycles of relapse and remission, with relapses typically requiring medication. Individuals who are consistently exposed to things like smoke, pet fur, pollen, soap, detergent, and wool can experience constant symptoms, leading to a reduced quality of life.
Persistent or repeated itchiness from AD can be not only irritating but also expensive to manage. A known complication of AD is Kaposi varicelliform eruption, related to a primary herpes infection. This means that blister-like sores can appear in the areas affected by AD and can spread to healthy skin. Treatment with a medication called acyclovir can help reduce these complications.
Furthermore, people with AD are more susceptible to skin infections caused by bacteria like Staphylococcus and Streptococcus.
Possible Complications When Diagnosed with Atopic Dermatitis
Here are some medical conditions you might come across:
- Kaposi varicelliform eruption
- Bacterial infection
- Uriticaria
Preventing Atopic Dermatitis
Patients should choose to wear clothes made of cotton and avoid those made from wool to avoid discomfort or irritation. Also, keeping the house a bit cooler can help minimize sweating and itching. Using a humidifier can be helpful to keep skin from getting too dry. Patients should also look out for and avoid any foods that seem to cause their AD symptoms to flare up.