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ARTICLE IN PRESS
BONSOI-4990; No. of Pages 2
Joint Bone Spine xxx (2020) xxx–xxx
Available online at
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Letter to the Editor
Panniculitis following baricitinib initiation for treatment of rheumatoid arthritis
a r t i c l e
i n f o
Keywords:
Drug related side effects and adverse reactions
Rheumatoid arthritis
JAK inhibitors
Panniculitis
Baricitinib is a janus kinase (JAK) inhibitor with initial approval
for treatment of adults with rheumatoid arthritis (RA) in 2017 [1]
that selectively inhibits JAK1 and JAK2 [2] and is under investigation
in juvenile dermatomyositis and systemic lupus erythematosus
(SLE) [3]. Different JAK inhibitors preferentially target various JAK
isoforms, which may result in differences in adverse event profiles
[4].
We describe what to our knowledge is the first reported case of
panniculitis developing in a patient receiving baricitinib for treatment of RA.
A 43-year-old woman with RA presented to clinic on day 23
of baricitinib therapy with a 20-day history of subacute, painful,
pruritic lesions on her extremities and buttocks (Fig. 1). On day
17 of therapy, she presented to an Emergency Department (ED)
for evaluation. Examinations revealed platelets of 228 K/mcL, Ddimer of < 0.27 mcg/mL, and a doppler ultrasound without evidence
of venous thrombus. The patient held baricitinib the days of and
after the ED visit (Days 17–18). She resumed baricitinib on Day 19,
and experienced acute worsening of symptoms within two days
(Fig. 2). After notifying us on day 22, we instructed her to discontinue baricitinib pending evaluation. The patient’s RA history
was complicated by hypersensitivity vasculitis and recalcitrance
to numerous biologic treatments. The patient received tofacitinib
for six months-years prior without adverse event but stopped due
to ineffectiveness. Her autoimmune serologic profile was notable
only for anti-cyclic citrullinated peptide antibodies and rheumatoid
factor. The patient’s medications included baricitinib 2 mg daily,
methotrexate 20 mg weekly, hydroxychloroquine 400 mg daily,
and prednisone 7.5 mg daily.
On physical examination, the patient’s posterior lower legs
demonstrated tender, indurated, coalescing hyperpigmented
plaques and subtle plaques on the anterior upper legs, buttocks and
forearm. Her musculoskeletal exam was notable for bilateral ankle
synovitis. The patient was instructed to discontinue baricitinib permanently with no other interventions. On Day 58, all evidence of
panniculitis was resolved.
The differential diagnosis included erythema nodosum, a drug
reaction to baricitinib, and vasculitides including erythema induratum. The normal d-dimer and negative ultrasound performed on
Fig. 1. Skin lesions on Day 17 after starting baricitinib.
day 17 made a thrombotic event unlikely. The exam findings were
satisfactory for diagnosis of panniculitis per dermatology. Given the
association of the onset of the lesions in relationship to baricitinib
initiation, the increase in intensity of inflammation documented in
photos after a short dechallenge and subsequent rechallenge, this
panniculitus was attributed to baricitinib. We submitted a report
describing this adverse event to the United States Federal Drug
Administration Medwatch program as well as to the manufacturer
of baricitinib. Baricitinib has potential applications in dermatomyositis and SLE which can manifest with panniculitis in a similar
distribution as our patient, potentially causing confusion in patients
treated with baricitinib with previous or new manifestations of
panniculitis.
We report what we believe to be the first case of panniculitis occurring with baricitinib. Our review of the literature revealed
a case of vasculitis in a patient receiving tofacitinib for RA with
histopathology suggestive of vasculitis and acute lobular panniculitis [5]. These cases highlight that clinicians must remain vigilant for
detecting novel medication-associated adverse reactions occurring
https://doi.org/10.1016/j.jbspin.2020.04.002
1297-319X/© 2020 Published by Elsevier Masson SAS on behalf of Société française de rhumatologie.
Please cite this article in press as: Fike A, et al. Panniculitis following baricitinib initiation for treatment of rheumatoid arthritis. Joint
Bone Spine (2020), https://doi.org/10.1016/j.jbspin.2020.04.002
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BONSOI-4990; No. of Pages 2
2
ARTICLE IN PRESS
Letter to the Editor / Joint Bone Spine xxx (2020) xxx–xxx
Musculoskeletal and Skin Diseases, National Institutes of Health.
Dominique Pichard, MD for her contributions in acquiring clinical
data.
References
[1] Olumiant product information, European public assessment report. European Medicines Agency. [Internet. Accessed February 11, 2020]. Available from: https://www.ema.europa.eu/en/medicines/human/EPAR/olumiant
#authorisation-details-section.
[2] Olumiant product information. Eli Lilly and Company. Indianapolis, IN
46285. Issued May 2018. [Internet. Accessed January 21, 2020]. Available
from: https://www.accessdata.fda.gov/drugsatfda docs/label/2018/207924Orig
1s000lbl.pdf.
[3] ClinicalTrials.gov. Baricitinib. [Internet. Accessed January 21, 2020]. Available from: https://clinicaltrials.gov/ct2/results?cond=&term=baricitinib&cntry=
&state=&city=&dist=.
[4] Schwartz D, Kanno Y, Villarino A, et al. JAK inhibition as a therapeutic strategy
for immune and inflammatory diseases. Nat Rev Drug Discov 2017;16:843–62.
[5] Muraviev Y, Radenska-Lopovok S, Lebedeva V, et al. Nodular polyarteritis as an
unforeseeable adverse reaction in RA patient treated with tofacitinib [abstract].
Ann Rheum Dis Suppl 2018;77:1370–1.
Fig. 2. Skin lesions on Day 22 after short dechallenge and rechallenge with baricitinib.
with newly-approved medications, especially considering potential confusion with disease-related manifestations.
Alice Fike a,∗
Rhett Kent b
Ann Biehl c
Michael M. Ward c
a Intramural Research Program, National Institutes of
Arthritis, Musculoskeletal and Skin Diseases (NIAMS),
10 Center Drive Rm 10N318 Bethesda, Maryland
20892, United States
b Forefront Dermatology, 8505 Arlington Blvd. Suite
210, Fairfax VA 22031, United States
c Clinical Trials and Outcomes Branch, Intramural
Research Program, National Institutes of Arthritis,
Musculoskeletal and Skin Diseases (NIAMS), National
Institutes of Health, 10 Center Drive Bethesda,
Maryland 20892, United States
Disclosure of interest
The authors declare that they have no competing interest.
Acknowledgments
∗ Corresponding author.
E-mail address: alice.fike@nih.gov (A. Fike)
Accepted 8 April 2020
Available online xxx
This research was financially supported by the Intramural
Research Program of the National Institute of Arthritis and
Please cite this article in press as: Fike A, et al. Panniculitis following baricitinib initiation for treatment of rheumatoid arthritis. Joint
Bone Spine (2020), https://doi.org/10.1016/j.jbspin.2020.04.002