WASHINGTON – mean it is often “woefully undertreated,” Robert Sidbury, MD, MPH, said at the annual Revolutionizing Atopic Dermatitis conference.
Identifying and mitigating triggers – such as irritation, contact allergy, and infection – is a cornerstone of treatment in infants, but tailored therapy with topical corticosteroids, topical calcineurin inhibitors (TCIs), and topical phosphodiesterase 4 (PDE4) inhibitors also have roles to play, said Dr. Sidbury, chief of dermatology at Seattle Children’s Hospital and professor in the department of pediatrics at the University of Washington, Seattle.
Views on the use of dupilumab as a systemic agent for severe infantile AD, meanwhile, have shifted significantly in the past year with the Food and Drug Administration approval of the biologic for children aged 6 months to 5 years and with extended experience with the biologic in all ages, including children, Lawrence F. Eichenfield, MD, professor of dermatology and pediatrics at the University of California, San Diego, said at the meeting.
The pediatric dermatologists spoke during a session devoted to AD in infants, during which the diagnosis of AD and the role – and risks – of food allergy testing were also discussed. Diagnosis, said Elaine C. Siegfried, MD, who also spoke during the session, requires careful consideration of mimicking conditions and a broader list of differential diagnoses in those infants with poor growth or frequent infections.
Here are some of the experts’ pearls for practice.
Diagnosing AD in infants
Among infants who are growing well and otherwise healthy, the infantile eczema phenotype encompasses AD, seborrheic dermatitis, contact dermatitis, psoriasis – and overlap of more than one of these conditions. “Overlap is common,” said Dr. Siegfried, professor of pediatrics and dermatology at Saint Louis University, and director of the division of pediatric dermatology at Cardinal Glennon Children’s Hospital.
(Initial topical treatment for all these conditions is similar, but optimal treatment may differ for young children with moderate to severe disease that requires systemic treatment, she said in an interview after the meeting.)
Sparing of the diaper area that reflects skin barrier integrity is a classic feature of AD in infants and can be a useful diagnostic sign. In addition, “hypopigmentation is more characteristic of psoriasis” than AD, whereas AD tends to be hyperpigmented, which is most obvious in skin-of-color patients, Dr. Siegfried said.
Disease-specific pigment changes may be related to microbial colonization – such as Malassezia-associated hypopigmentation – or cell turnover, which is faster in psoriasis and slower in AD – with corresponding differences in pigment retention, and may be more obvious in children than adults, she said.
A less common scenario is dermatitis in infants who are not growing well. For these patients, she noted, the differential diagnosis includes metabolic or immune deficiency dermatitis as well as a variety of genodermatoses.
Generalized redness and scaling present on the first day of life is suggestive of non-atopic dermatitis. “If you’re born with red scaly skin, that’s very different than if you develop red skin in the first month or two of life,” Dr. Siegfried said.
When there is diaper area involvement with AD, contact dermatitis, impetigo, and Candida may be complicating factors. And in infants with other morbidities – especially those who are not growing well – diaper area involvement suggests a broader differential diagnosis. “I implore you, if you see children, make sure you weigh and measure them at every appointment,” she said.
Dr. Siegfried has seen infants with Netherton syndrome, and those with cystic fibrosis with zinc deficiency, for instance, presenting with “an eczematous-like picture,” diaper-area involvement, and other morbidities.
For infants with AD, she maintains a high index of suspicion for secondary infections such as molluscum, herpes simplex virus (HSV) with or without streptococci, scabies, tinea, and group A streptococci. “Secondary infections ... may be incognito,” she said. “Look for subtle signs. Even molluscum can be very subtle.”
Secondary allergic contact dermatitis is also common although it’s “technically difficult to confirm the diagnosis,” she said. Patch testing in infants is technically challenging, sensitivity is low, and monosensitization is uncommon. “So I do initial empiric topical allergen avoidance,” she said, keeping in mind ubiquitous and avoidable topical allergens such as Kathon, cocamidopropyl betaine, propylene glycol, disperse blue, and adhesives.