CHICAGO — One of the more recent developments in sunscreen technology is the addition of iron oxide to mineral sunscreens.
Iron oxide is “an excellent pigment” that absorbs and blocks visible light, which is particularly important in individuals with Fitzpatrick skin types III-VI, Zoe D. Draelos, MD, consulting professor of dermatology at Duke University, Durham, North Carolina, said at the Pigmentation Disorders Exchange symposium.
Susan C. Taylor, MD, professor of dermatology at the University of Pennsylvania, Philadelphia, who spoke at the conference, also recommended tinted sunscreen with iron oxide for patients with skin of color. “It still needs to be broad spectrum,” she said, “and at least an SPF [Sun Protection Factor] 30.”
When blended with mineral sunscreens, iron oxide can reduce transmission of visible light by 90% and can protect patients from hyperpigmentation. Iron oxide comes in different colors blended together for various degrees of tinting.
Dr. Taylor noted that iron oxide is listed under the inactive ingredients. “The literature indicates a 3% concentration to aim for, but we don’t know the concentration in most of the products,” she added.
During her presentation, Dr. Draelos noted that inorganic sunscreens, such as zinc oxide and titanium oxides, are highly effective but make the skin white and pasty. To address this issue, many companies are now grinding these materials into such small particles that they are transparent.
“That’s great, except the smaller the particle is, the less UV [ultraviolet] radiation it reflects and that lowers the [SPF],” she said.
In addition to providing photoprotection, sunscreens in general provide protection from nanoparticles in tobacco and combustion, such as traffic exhaust, which can harm skin over time. “Moisturizers and sunscreens are the best way to protect against pollution and tobacco nanoparticle damage, which can contribute to inflammation,” she noted. They create a film over the skin and trap the nanoparticles.
Start the Patient Visit With a Photoprotection Talk
At the meeting, Dr. Taylor recommended that for all patients with hypopigmentation and hyperpigmentation disorders, “treatment really begins with photoprotection.”
She acknowledged that photoprotection discussions, including the basics of seeking shade, wearing protective clothing, and avoiding midday sun, often come at the end of the patient visit but she urged dermatologists to make that the first topic instead.
Dr. Taylor said a question often asked of patients of color about prolonged sun exposure — whether their skin turns bright red after too much sun — may get a negative reply. The better question is whether the patient has experienced tender skin after too much sun — which can signify a sunburn, she said.
Dr. Draelos reported no relevant financial relationships. Dr. Taylor reported financial relationships and grant support from multiple pharmaceutical companies.
A version of this article first appeared on Medscape.com.