‘Maybe we should listen’: Allergies from sesame to sunscreen may aggravate hair loss

Key takeaways:

• After being named a “big nine” food allergen, sesame was found to be associated with alopecia areata in children.
• Chemical sunscreens applied near the hairline were also linked to frontal fibrosing alopecia.

MIAMI BEACH, Fla. — Atopy from food allergies to environmental factors can increase hair loss prevalence among children and adults, according to a presentation at South Beach Symposium.

“The thing that I want you to take home today is the role of allergies in immune conditions,” Natasha A. Mesinkovska, MD, PhD, vice chair of clinical research in the department of dermatology at the University of California, Irvine, said during her presentation. “What we really should be doing for both adults and kids is asking them what they are allergic to, because if you treat the allergy, you can actually prevent people’s hair from falling out.”

According to a study conducted by Sorrell and colleagues, atopy, including food allergies, is the No. 1 comorbidity in alopecia areata among adults and children. In fact, food allergies are on the rise in the U.S., with 2% to 3% of adults and 8% of children reporting a food allergy, according to a 2023 study from Bright and colleagues. While milk, fish and peanuts may be the most common food allergies, another inflammatory ingredient has been traced to hair loss — sesame.

“I had a lot of alopecia areata kids complaining of belly aches, so I ran food panels on them and 9 out of 10 tested positive for a sesame allergy,” Mesinkovska said. “I thought to myself, how did this happen and why are all these kids testing positive?”

As Healio previously reported, sesame became a major food allergen in the U.S. on Jan. 1, 2023, after former president Biden signed into law the Food Allergy Safety, Treatment, Education and Research Act in April 2021.

The law requires food manufacturers and companies handling food to avoid sesame cross contamination and provide labels on foods that did contain the allergen. However, as Healio previously reported, this law has unintended consequences.

Companies considered the new sesame cross-contamination laws “too stringent” and instead decided it would be easier to sprinkle a little bit of sesame flour into every food item and provide a label indicating the addition of sesame to bypass the cross-contamination regulations.

As a result, patients with a sesame allergy were experiencing reactions to previously safe foods, causing a surge in comorbidity prevalences like hair loss.

“I will tell you that I have had two kids that were unable to go on [Janus kinase (JAK)] inhibitors, so we had them stop eating sesame and we stopped their alopecia areata,” Mesinkovska said. “You could say, well that’s only two for two, but for them, it was life changing.”

In another case presented by Mesinkovska, a patient with alopecia areata on JAK inhibitors who was previously doing well suddenly experienced an acute flare of facial dermatitis and increased hair loss. When Mesinkovska asked what the patient thought may be causing this flare, the patient stated they were cutting olive trees in her neighborhood, and she believes she may be allergic to the olive trees.

“When she told me that I just thought, ‘yeah, yeah sure,’” Mesinkovska said sarcastically. “So, I ran an allergy panel and guess what comes up as very, very positive? Olive trees.”

According to her presentation, food allergies are not the only factors that may cause hair loss.

Frontal fibrosing alopecia, a type of hair loss that involves many signs and symptoms outside of hair loss such as hyperpigmentation, facial papules and even forehead wrinkles, can be aggravated by chemical sunscreen.

“A study in the U.K. found that people that have this condition actually tended to use year-round sunscreens,” Mesinkovska said. “Dr. Sinclair’s group in Australia also showed a patient who stopped using sunscreen and her hair came back.”

Sinclair Dermatology now advises patients with FFA to avoid applying sunscreen products to the hairline and instead wear a wide-brimmed hat or simply avoid the sun.

“I definitely stay away from chemical sunscreens and just don’t let my patients apply it, definitely not on that area,” Mesinkovska said.

The connection between allergies, inflammation and hair loss may be complicated, but Mesinkovska recommends that it should be considered when treating patients. Running serum IgE testing on patients with alopecia areata may elucidate the root cause of symptoms as it provides high specificity and a good positive predictive value.

While dermatologists are the foremost experts on skin, hair and nails, patients themselves may offer insight into what exactly is occurring in their bodies. Mesinkovska encourages dermatologists to listen to their patients’ concerns and ideas about their disease, recalling her encounter with her patient that had the olive tree allergy along with hair loss.

“Guess who was right? She was,” Mesinkovska said. “So maybe we should listen.”

References:

• Adoori N, et al. Br J Dermatol. 2016; doi: 10.1111/bjd.14535.
• Bright DM, et al. Am Fam Physician. 2023;108(2):159-165.
• Frontal Fibrosing Alopecia (FFA). https://www.sinclairdermatology.com.au/wp-content/uploads/2019/05/Brochure-Frontal-Fibrosing-Alopecia.pdf. Accessed Feb. 10, 2025.
• Sorrell J, et al. Pediatr Dermatol. 2017;doi:10.1111/pde.13238.