Since the U.S. Food and Drug Administration first approved a Janus kinase (JAK) inhibitor in 2011, the number of these drugs available—and their treatment indications—has steadily increased. Prescribers are familiar with the benefits and risks of these drugs, including a higher risk of heart disease and cancer. But one side effect is often overlooked, especially by specialists outside of dermatology: acne. Although less serious than some other side effects, JAK inhibitor-associated acne—or JAKne—can be a cause for concern for patients.
“Your physical appearance and the way you present yourself to the world is an important part of your sense of self and living life on your own terms,” said Dr. Arash Mostaghimi, chief of inpatient dermatology at Brigham and Women’s Hospital in Boston. “I think that educating people about (JAKne) and then treating it when it occurs should be a normal part of managing these medications.”
What is JAKne?
JAKne generally looks like other types of acne, explained Dr. Janelle Nassim, a dermatologist at Indiana University Health with a practice in Carmel, Indiana. “It can affect the same areas as typical acne, including the face, chest, back, neck and upper shoulders.”
Although it looks like a typical form of acne, it is not clear what causes these rashes in patients taking JAK inhibitors.
“We don’t understand the underlying pathophysiology,” Mostaghimi said. “It looks like acne, but we don’t know if the underlying inflammatory process is the same or if it’s different.”
In a 2023 systematic review of clinical trials, Mostaghimi and colleagues found that patients taking any JAK inhibitor were nearly four times more likely to develop acne than those taking a placebo, with the risk varying between drugs. Patients taking JAK inhibitors for skin conditions had a higher risk of acne than those taking drugs for other indications. However, Mostaghimi believes this finding is the result of selection bias.
In studies on rheumatic or gastrointestinal diseases, participants are not allowed to mention side effects such as acne, unlike in studies on skin diseases. “Clinically, I have seen it in patients of all indications,” he explained.
Patients with a history of acne seem more likely to develop this side effect, although there are no official studies on risk factors, he continued. In Mostaghimi’s own clinical experience, JAKne is also more common in younger patients, but it can affect anyone. “I’ve seen 70-year-olds get acne – patients who never had a problem their whole life – when they took a JAK inhibitor,” he said.
This problem also seems to occur more frequently at the beginning of treatment, he added, and may improve over time as the patient continues drug treatment.
How do you treat it?
“I think in other specialties, people often feel uncomfortable discussing skin conditions or mentioning acne,” Mostaghimi said. The most important steps are to be aware of this potential side effect and to address it when you notice it.
“Tell me: I notice that your skin is changing. Some patients who take JAK inhibitors develop more acne. Have you noticed this? And if so, does it bother you?” he continued.
Generally, JAKne is mild to moderate, Nassim explained, and if non-dermatologists agree, they can prescribe patients a topical first-line treatment. Mostaghimi recommends prescribing a 1% clindamycin lotion or gel. In addition, patients can use a wash containing benzoyl peroxide (4% or 10%) in combination with a gentle retinoid such as adapalene. (Both treatments are now available over the counter.)
For patients with scalp or hairline involvement, he often prescribes a 2% ketoconazole shampoo, which patients can use to wash their scalp, face, chest and back in the shower.
If these initial treatments do not respond, refer the skin to a dermatologist for further examination.
“Ultimately, referral to a dermatologist is the best course of action,” Nassim said. “I’ve had patients on JAK inhibitors who improved with topical acne treatments and some who required more aggressive treatment with oral medications,” she said.
Mostaghimi reported consulting fees from AbbVie, Concert Pharmaceuticals, Pfizer, and 3Derm Systems; research funding from Incyte Corporation, Aclaris Therapeutics, Eli Lilly and Company, and Concert Pharmaceuticals; personal fees from Equillium, ASLAN Pharmaceuticals, ACOM, and Boehringer Ingelheim; and advisory board fees from Fig.1 Beauty, Eli Lilly and Company, Pfizer, and Hims & Hers Health. Nassim had no relevant disclosures to disclose.
