Since the first Food and Drug Administration approval of a Janus kinase (JAK) inhibitor in 2011, the number of these medications available — and their treatment indications — have continued to grow. Prescribing physicians are familiar with the benefits and risks for these drugs, including higher risk for cardiac events and malignancy; however, one adverse effect may be overlooked, especially by specialties outside of dermatology: acne. Though less serious than some other side effects, JAK inhibitor–associated acne — JAKne, for short — can be a concern for patients.
“Your physical appearance and how you present yourself to the world is an important part of your self-confidence and living life on your own terms,” said Arash Mostaghimi, MD, the director of inpatient dermatology at Brigham and Women’s Hospital in Boston, Massachusetts. “I think letting people know about [JAKne] and then addressing it when it occurs should be a normal part of managing these medications.”
What Is JAKne?
JAKne generally looks like other kinds of acne, explained Janelle Nassim, MD, director of laser and cosmetic dermatology at the Indiana University School of Medicine, Indianapolis. “It can affect the same areas that typical acne affects, including the face, chest, back, neck, and upper shoulders.”
Though it appears like typical forms of acne, it is not clear what drives these skin eruptions in patients taking JAK inhibitors.
courtesy Brigham and Women's Hospital
Dr. Arash Mostaghimi
“We don’t understand the underlying pathophysiology,” Dr. Mostaghimi said. “It looks like acne, but we don’t know if the exact underlying inflammatory process is the same or if it’s different.”
In a 2023 systematic review of clinical studies, Dr. Mostaghimi and colleagues found that patients on any JAK inhibitor were nearly four times more likely to experience acne than patients who received placebo, but risk varied between medications. Patients taking JAK inhibitors for skin conditions had higher risk for acne than those given the medications for other indications. However, Dr. Mostaghimi thinks this finding is the result of selection bias.
Participants may not mention side effects like acne in trials for rheumatologic or gastrointestinal conditions, he said, unlike in trials for skin conditions. “Clinically, I’ve seen it in patients across every indication.”
Patients with a history of acne seem to be more likely to develop this side effect, though formal studies looking into risk factors are lacking. In Dr. Mostaghimi’s own clinical experience, JAKne is also more common in younger patients, but it can happen to anyone. “I’ve seen 70-year-olds develop acne — patients who’ve never had an issue their whole life — when they’re taking a JAK inhibitor.”
This issue also appears to be more common earlier in treatment, he added, and may improve over time as a patient continues with the medication.
How Do You Treat It?
“I think in other specialties, you will often feel awkward addressing skin conditions or pointing out acne,” Dr. Mostaghimi said. The most important steps are being aware of this potential side effect, and if you see it practice, to bring it up.
“Say: I’m noticing there’s some changes in your skin. Some patients on JAK inhibitors develop more acne. Have you noticed this? And if so, is this bothering you?”
Generally, JAKne is mild to moderate, explained Dr. Nassim, and if non-dermatologists are comfortable, they can prescribe a first-line topical regimen for patients. Dr. Mostaghimi recommends prescribing a clindamycin 1% lotion or gel. In addition, patients can use a benzoyl peroxide wash (4% or 10%) combined with a gentle retinoid, such as adapalene. (Both of these treatments are now available over the counter.)
courtesy Harvard Medical School
Dr. Janelle Nassim
In patients with scalp or hairline involvement, he often prescribes a ketoconazole 2% shampoo, which patients can use to wash their scalp, face, chest, and back in the shower.
If they aren’t responding to these initial treatments, then refer to a dermatologist for further assessment.
“Ultimately, referring to a dermatologist is the best course of action,” Dr. Nassim said. “I have had patients on JAK inhibitors who improved with topical acne treatments, and some that required more aggressive treatment with oral medications.”
Dr. Mostaghimi reported consulting fees from AbbVie, Concert Pharmaceuticals, Pfizer, and 3Derm Systems; research funding from Incyte, Aclaris Therapeutics, Eli Lilly, and Concert Pharmaceuticals; personal fees from Equillium, ASLAN Pharmaceuticals, ACOM, and Boehringer Ingelheim; and advisory board fees from Fig.1 Beauty, Eli Lilly, Pfizer, and Hims & Hers Health. Dr. Nassim had no relevant disclosures.
A version of this article first appeared on Medscape.com.