Diagnostic Challenges, featuring Vivian Shi, MD, FAAD
Important Considerations for an Accurate AD Diagnosis
How do we get to an appropriate and timely diagnosis for atopic dermatitis (AD)? That is the million-dollar question. If we cannot make a timely diagnosis, we cannot design an appropriate and individualized treatment, and patients won’t get better. To make the correct diagnosis, one of the most important things is to actually recognize the different patterns of AD: how the skin feels (symptoms) and looks (signs) (Table 1).
Recognizing symptom is the first step in diagnosing AD. Unlike many other conditions where rash develops before itching, eczema is the itch that rashes, meaning itching may start before any visible rash. As a natural reflex, we scratch where the skin itches, then rash development which leads to even more itching – this is known as the “itch-and-scratch cycle”. An important goal of AD treatment is to help patients break this cycle.
A commonly used diagnostic criteria for AD are the Hanifin-Rajka criteria, which is useful for identifying the classic signs of AD. There are a number of major criteria and minor criteria (Table 2), but at the base of the diagnosis, the patient should have rash and itching. While AD can develop all over the body, there are classic areas where it develops in a diagnostic pattern depending on the age of the patient. For example, when babies develop AD lesions, these typically present on the cheeks. As the child ages, they develop lesions more in the skin folds, or the inner side of the elbows and the back of the knees.
When we get to adulthood, there is a progression with more arm, leg, hand, and foot involvement.
Diagnosing classic AD, many times, is checking off a number of those criteria boxes, but the real challenge is that not every case of AD will present exactly like the textbook definition. There is a wide spectrum of eczematous presentations. The word eczema just means dermatitis or inflammation of the skin of any kind; any time the skin has redness, swelling, or even itching, the symptoms can be called dermatitis or eczema. These symptoms may signal a number of other conditions, including seborrheic dermatitis or irritant hand dermatitis. Homing in on the actual diagnosis will allow us to design the appropriate treatment and give our patients and caregivers appropriate information on what to expect in the long term.
AD is remitting and relapsing disease; there are good days and bad days. The treatment goal is to have more good days and less bad days. When the patient comes to see me with their family, we are only catching them in a snapshot which may not tell the full story of their AD in between doctor visits. I tend to ask my patients to show me some photographs of their affected areas. Now that we are in the era of smartphones, my job has gotten a lot easier, as patients can take photos to track their disease progression. Even when the skin doesn’t look that severe during the doctor visit, their documentations and photo records allow me to able get a fuller picture of how their skin looked in between visits. Conversely, if the skin is really bad on the day that they are visiting, I can get a better idea about what is the best they have looked in this anatomical area.
There are also other tricks for diagnosing AD. Many patients often have a cluster of allergy diseases, including AD, food allergies, asthma, and hay fever (also known as allergic rhinitis or seasonal allergies) . Many times, even when the skin does not have an active eczema rash, I can use other clues to determine whether that the patient is has an “allergic” tendency. One of these common signs are Dennie-Morgan lines, or prominent skin folds on the lower eyelid. In addition, many of these patients will have a darker skin color around the eyes and the nose from chronic rubbing of these areas due to itching and runny nose. Patients with eczema may also have hyperlinear palms, in which the lines on their palms are more prominent, rough, and groovy. These tricks can help identify a patient who is at risk for AD.
Experiences of Racial-Ethnic Minority Groups
In general, not enough is understood regarding conditions in skin of color skin; this is true in AD as well. The majority of the research on skin and on AD mainly has been done in developed countries and in Caucasian individuals. Most of the dermatology textbook uses Caucasian photos and cases. But this is changing with the rapidly growing social awareness. It is important that we bring attention to this matter and knowledge gap (Table 3).
The clinical presentation of AD can be different in various skin types. AD in an Asian person can looks more similar to that of psoriasis in a Caucasian person than of AD. In my experience of volunteering in Southeast and East Asia earlier in my career, I admittedly had trouble distinguishing psoriasis and AD in these patients. This distinction is getting more attention through the research of physician scientists such as Dr Emma Guttman, showing exactly the above.
Socioeconomic barriers and access to health care resources may be more common in people of color in our country and globally, these patients often present much later to the doctor for their AD. Their AD also tends to be more severe by the time they present to a doctor; this is both because of social reasons and also intrinsically in their disease. For example, research have shown that African Americans tend to have drier skin and more severe AD. In addition, there may be differential responses in various treatments across skin of color. We should also keep in mind that there can also be language barriers, cultural differences in skin care practices, and preferences in AD treatments.
People of color are more likely to have certain mutations in the skin that predispose them to getting AD and more severe AD. African Americans, for example, have a special variant of filaggrin (FLG) called FLG2 that has a much higher mutation rate. That already sets them at a higher risk of getting AD, because they are more likely to get dry or ashy skin, which can allow microorganisms and allergens to enter through a broken protective layer and increase evaporation of water from the skin.
In addition, people of color are also more likely to get other skin findings associated with AD, such as Dennie-Morgan lines underneath the eyes. They are also more likely to have a special variant of AD called papular eczema, in which little bumps develop around the hair follicles that patients often identify as “itchy goosebumps.” Patient with this presentation may be misdiagnosed, may not receive the appropriate AD treatment.
Gaining awareness on the different clinical presentations across skin of color is so important, but so is understanding the differences in treatment approaches. For example, some of the topical corticosteroids that we use to treat eczema can cause temporary pigment loss in individuals with skin of color, and that can be a barrier in compliance or adherence in treatment. Often, as providers, we do not consciously think about these patient experiences and counsel our patients and families appropriately. That is a lost opportunity in communication and potentially in having a good outcome.
Depending on which research you look at, the prevalence for AD can be up to 20% in children and up to 10% in adults. These are global numbers and may vary depending on which region/country is examined. For example, in the south central of U.S. where I practice, the majority of my AD patients are skin of color. In the U.S., our racial demographics are changing rapidly and becoming more diversified. We will see a rising demographic of skin of color, especially in the Hispanic, multiracial, and Asian American populations. The American skin phenotype will be changing rapidly in the next few decades, and as dermatologists, we are in the forefront of recognizing these changes and being able to counsel our patients and implement treatments accordingly.
Looking Beyond the Skin
It may sound cliché, but I always say, “eczema is more than skin deep”. It is associated with other allergic conditions such asthma, food allergies, and hay fever, but beyond that, it is the mind-body interaction and life interference that many patients and their families experience. This ultimately affects their quality of life (QoL). For example, AD can really add stress to the family and taking care of a child with AD can be a full time job. As evidenced in the collaborate research I have done with parent groups, some caregivers report having to take time off work or quit their job altogether to take care of a child with moderate to severe AD. That workload is added to exponentially when there is more than one family member with AD.
We also should consider the mental health perspectives for the patient and the family. Older individuals with AD are more likely to have anxiety and depression. The effort required to take care of their skin can decrease their productivity in school and work, which may indirectly lead to financial issues and affect career development or choices. In younger children, behavioral or cognitive interference can present on a wide spectrum. Children with AD, because of a lack of sleep and chronic itching, can exhibit behavior anywhere from being withdrawn to displaying hyperactivity. In these hyperactive instances, children may appear to be disobedient and commonly mislabeled as troublemakers in school. In reality, the disrupted sleep and itching can greatly affect their behavior. These are factors that we need to be cognizant about as physicians to help parents and the community understand the challenges AD patients are facing.The most important aspect of AD management is fostering partnership with the patient and their family. They are the true experts in AD, because they live in and care for their skin every day. The most valuable knowledge and information come from them. However, the challenge is continuing management when the patient can only come to a dermatologist’s office ever so often, whether that is every other month; every 3 months; or, for those who live further away from the eczema center, visits can be as far as a year apart. How do we as physicians monitor AD disease course without physically being present every day? It’s not easy to get a clear picture of the remissions and flares, and know which treatments worked and what did not.
Luckily, a number of trackers are now available to help patients and families keep diaries and set treatment reminders. One of these trackers, EczemaWise, was developed in collaboration with the National Eczema Association. Patients and families can enter their severity, triggers, and document their medication usage. This can help patients have a good summary of their disease course for the doctor when they do meet.
This active role in tracking leads to the era of shared decision making (Table 4). Traditionally, the doctor would say, “This is what you’re going to do, and you’re going to do it”; it was very authoritarian. More and more so, the shared-decision model creates a mutual partnership in which patients/caregivers as well as doctors both have equal input on the treatment goals and plans. This method of care has been shown to lead to better relationships between the patient and the doctor, better understanding of the challenges that both sides face, and more equal ground expectations. It has decreased misunderstanding and improved treatment adherence and, ultimately, outcomes. Accurate information gathering and fostering trust are essential parts of AD care. The information gained and relationship cultivated are beneficial for all sides.
