Medical therapy for seborrheic dermatitis (SD) and rosacea, skin disorders that are frequently occur together in patients, was discussed at the recent American Academy of Dermatology annual meeting in San Diego.
Dr. Benjamin Ungar, assistant professor of dermatology at the Icahn School of Medicine at Mt. Sinai, explained that SD primarily occurs in areas with high concentrations of oil-producing sebaceous glands — the scalp, eyebrows and glabella, cheeks and bearded areas of the face — and may also extend to the upper chest and back. SD most commonly occurs during early infancy, puberty and from ages 40 to 60. The condition is estimated to affect 1-3% of adult Americans, but its prevalence among Black Americans may be as high as 6.5%. Dr. Ungar pointed out that as much as half of the population experiences dandruff, which is on the SD spectrum, at some point in their lives.
Dr. Ungar said there has been an unmet need for new therapies for SD, noting that the most common treatments are topical antifungals, calcineurin inhibitors such as tacrolimus and pimecrolimus, and topical steroids. “But topical steroids worsen rosacea, and when you have a common comorbid condition, you need to be mindful of that,” he warned. The FDA recently approved topical roflumilast foam, a PDE4 inhibitor that has anti-inflammatory properties, for the treatment of SD. In a phase III clinical trial of 457 patients, 79.5% were clear or almost clear after eight weeks, compared to 58% of those using a placebo.
The pathophysiology of SD and rosacea bear some similarities, Dr. Ungar noted. Both diseases show abnormally high expression of genes related to the Th1 and Th17 immune response pathways, which result in inflammation and skin barrier dysfunction.
“All of the available treatments for papulopustular rosacea are one way or another attacking the disease from an antimicrobial perspective,” Dr. Ungar said. “And so, similar to seborrheic dermatitis, a question we have to ask is whether rosacea is driven by microbial dysregulation or dysbiosis, or is treatment addressing one aspect and missing another part?”
He noted that a variety of potential therapies have been identified that target the full range of rosacea signs and symptoms, and he is hopeful that successful treatments for this complex disease will emerge, especially ones that address persistent erythema.