Cutaneous T-cell lymphoma in a JAK inhibitor patient: A case report

Abstract

Janus kinase (JAK) inhibitors are novel molecules increasingly prescribed for various dermatologic conditions. However, the Food and Drug Administration recently reported increased risks of malignancy in patients taking this class of medication. To shed more light on this potential adverse effect, we present a patient with cutaneous T-cell lymphoma possibly associated with his treatment with a JAK inhibitor for atopic dermatitis. To our knowledge, there are no reported cases of cutaneous T-cell lymphoma in association with JAK inhibitors in the literature. We highlight the importance of remaining cautious when prescribing this new class of medication, especially in patients with risk factors for malignancy. Moreover, when faced with atypical presentations of atopic dermatitis, we stress the need for a biopsy to make the correct diagnosis prior to treatment. Lastly, we encourage further studies to better characterize the malignancy risk associated with JAK inhibitors.

Keywords: JAK inhibitor; cutaneous T-cell lymphoma; upadacitinib.

Figure 1.

Presentation of the patient’s cutaneous T-cell lymphoma. (a) Leonine facies. (b) Alopecia and scalp hyperkeratosis. (c) Keratosis pilaris-like perifollicular papules coalescing into erythematous infiltrated plaques.