Seborrheic Dermatitis Progress Meaningful for Skin of Color

New York — Seborrheic dermatitis (SD) is a common and shared disorder across populations, but it is the third most common dermatologic complaint that Black individuals bring to the dermatologist and deserves more attention not only in this group but also overall, now that there is an approved therapy with an array of alternatives and adjunctive medications, according to Shawn Kwatra, MD.

The list of therapies effective against SD, often employed in combination, is lengthy, but topical 0.3% roflumilast foam (Zoryve), approved late last year for treating SD, has a high rate of efficacy and should now be considered a first-line treatment option, according to Kwatra, professor and chair of the Department of Dermatology, University of Maryland School of Medicine, Baltimore.

New Approved Therapy Draws Attention to SD

Emphasizing that topical roflumilast does not necessarily replace the use of over-the-counter shampoos and emollients or a list of prescription drugs used off-label to control this condition, he said it is also important for another reason.

“It shines a light on this disease,” said Kwatra, speaking at the 2024 Skin of Color Update. While his comments were focused primarily on individuals with darker skin, his major take home messages were broadly relevant across skin types.

Kwatra acknowledged that for years he “had not given seborrheic dermatitis the respect that it deserves” even though this condition comes after only acne and eczema as chief complaints among Black individuals seeing a dermatologist. The estimated global incidence is 5%, according to Kwatra, but he considers this estimate of an often “forgotten disease” too low.

One reason is that many individuals self-treat with over-the-counter solutions and never bring the complaint to a clinician. Kwatra said that he now looks for it routinely and points it out to patients who have come to him for another reason.

In patients with darker skin, the signs of SD can differ. While scalp involvement is generally easy to identify across skin types, the inflammation and erythema, sebum production, scaling and itch, and Malassezia that accompanies and drives SD might be missed in a patient with darker skin without specifically looking for these signs.

Skin and Gut Microbiome Involvement Suspected

The underlying causes of SD are understood as an inflammatory process involving keratinocyte disruption and proliferation that ultimately impairs skin barrier function, causes water loss, and produces scale stemming from stratum corneum, but Kwatra said that there is increasing evidence of a major role for both the skin and gut microbiome.

In regard to the skin microbiome, Malassezia has long been recognized as linked to SD and is a target of treatment, but evidence that the gut microbiome might be participating is relatively new. One clue comes from the fact that oral antifungal therapies, such as itraconazole, are known to reduce risk for SD relapse, an effect that might be a function of their ability to modulate the gut microbiome, according to Kwatra.

Topical roflumilast, a PDE-4 inhibitor, was effective for SD in a vehicle-controlled phase 3 trial published in 2023. Kwatra characterized the adverse event profile as “pretty clean,” but he emphasized that a role for many other strategies remains. This is particularly true for challenging forms of SD. For example, topical tacrolimus provided meaningful protection against relapse over a period of more than 6 months in a 2021 trial that enrolled patients with severe facial SD.

The topical Janus kinase inhibitor ruxolitinib, 1.5%, (approved for atopic dermatitis and vitiligo) has also been reported to be effective for refractory facial SD.

Given the heterogeneity of the presentation of SD and the value of combining different mechanisms of action, Kwatra does not think any drug by itself will be a cure for SD. However, the chances of success with current drug combinations are high.

It is for this reason that Kwatra encourages clinicians to look for this disease routinely, including among patients who have a different presenting complaint. “Patients do not always bring it up, so bring it up,” he said.

This is good advice, according to Andrew F. Alexis, MD, MPH, professor of clinical dermatology and Vice-chair for Diversity and Inclusion of the Department of Dermatology , Weill Cornell Medicine, New York City. He agreed that the recent introduction of a therapy approved by the US Food and Drug Administration is an impetus to look for SD and to talk with patients about treatment options.

In addition, while he also considers roflumilast foam to be a first-line drug, he agreed that combination therapies might be needed to increase the likely of rapid control of scalp and skin involvement. “SD is probably underestimated as a clinical problem, and we do have good treatments to offer for the patients who are affected,” he said at the meeting.

Kwatra reported no relevant disclosures. Alexis reported financial relationships with more than 25 pharmaceutical companies.

Ted Bosworth is a medical journalist based in New York City.