Differences underlie pathology, indicating efficacy of atopic dermatitis treatments may vary

Dr. Silverberg

Not only is atopic dermatitis considerably more prevalent in children than adults (12% versus 7.2%), the prevalence of its particular phenotypes and subtypes can also vary markedly across different age groups. For example, in adults, the condition more frequently presents on the hands or feet.

“The key challenge for adult eczema is we often see less flexural disease and more of those other subsets,” says Jonathan Silverberg, associate professor and director of the Northwestern Medicine Multidisciplinary Eczema Center and of the Contact Dermatitis Clinic at Northwestern Memorial Hospital in Chicago. “Couple that with the fact that the differential diagnoses are much broader, and a couple of entities in the differential diagnoses are more common, and atopic dermatitis becomes a very challenging diagnosis.”

Other conditions, such as contact dermatitis, cutaneous T-cell lymphoma and cutaneous/systemic lupus erythematosus need to be ruled out, and then “atopic dermatitis almost becomes a diagnosis of exclusion,” he says, with the patient meeting the clinical criteria after other conditions have been ruled out.

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As atopic dermatitis tends to present differently in adults and children, it is likely that there are also some differences in the underlying pathological disease processes, meaning that different treatment modalities may prove to be more effective in adults than children and vice versa. Currently, it is difficult to compare the efficacy of different treatments in children as adults, because, as treatments are first licensed based on studies in adults, very little data often exist on effectiveness in children, and even less from head-to-head comparative trials.

“Logically, there will be differences as some of these pathways are more relevant in adults than children, that is why there is a real rationale to study children separately from adults and not to make assumptions that a child would respond as an adult would, or vice versa,” he explains.

“In reality there may be a variety of different immune mechanisms implicated and some more relevant in children than adults. These are all very theoretical at this point but they may not be for very long. In the next few years I think we will have some really important data to digest between children and adults across a variety of different immune pathways.”

However, right now the assumption is what works in an adult will work in a child but taking into account safety concerns about use in children, for example with agents such as oral systemic suppressing agents, he says. And the same targeted indications used for adults, based on crude physical examination or objective assessment, such as body surface area involved, or the intensity of the lesions, have to be utilized for children.

Despite the lower prevalence of atopic dermatitis among adults, an estimated 16.5 million live with the condition in the United States, but if one were to visit a dermatologist’s office and see the number of patients, one might assume that there are far fewer.

Lack of health insurance will keep some patients away from dermatologists’ outpatient clinics, but often patients with insurance coverage will also end up seeking treatment elsewhere.

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Atopic dermatitis is an incredibly volatile disease, and there is a subset of patients who experience dramatic flares in their disease that require rapid access. If they can’t get a day off from work during standard outpatient hours, cannot get an appointment with the dermatologist within the next six months, don’t have transportation to get there easily, or have childcare or other caring responsibilities, they will seek more convenient care from the emergency room or a hospital, Dr. Silverberg explains.

Not only does this expose them to potential healthcare infections, but from a cost and economic point of view, treatment in the emergency room or hospital system is “orders of magnitude more expensive” than it would be to be treated in the outpatient setting.

“Many of these patients are actually incurring high expenses both to themselves and to the healthcare system because they are not able to utilize the less expensive outpatient care,” he says. “There are many aspects of the healthcare system that can really be tweaked in order to improve access for the atopic dermatitis patient who is getting that severe itchy flare.”