Case Report Shows Dupilumab Effective at Controlling Exaggerated Insect-Bite Response in Setting of CLL

The atopic dermatitis medication dupilumab (Dupixent; Sanofi/Regeneron) may be a meaningful treatment option for patients with chronic lymphocytic leukemia (CLL) who experience persistent exaggerated responses to insect bites, according to a new report.

The case report was published in JAAD Case Reports.

Man scratching a bug bite | Image credit: Oporty786 - stock.adobe.com

Corresponding author William Guo, MD, of Stony Brook University’s Renaissance School of Medicine, and colleagues, explained that the patient in the case was a 55-year-old man who sought care from their dermatology clinic after experiencing extreme cutaneous reactions to insect bites for the previous 2 years.

“The patient would experience marked edema and erythema that developed days after witnessed insect bites,” Guo and colleagues wrote. “This would be occasionally followed by blistering and resultant skin ulcerations that healed with scarring.”

Unfortunately, the patient said the insect bites were essentially unavoidable, given that he worked as a landscaper.

The patient had recently been diagnosed with CLL, and said the onset of his extreme cutaneous reactions to insect bites coincided with the cancer diagnosis. He also had a history of depression, gastroesophageal reflux disease, and asthma. He had been taking bupropion, omeprazole, budesonide-formoterol, and trazodone, the authors said.

Physicians performed a skin biopsy, which “displayed an ulcer with papillary and reticular perivascular and interstitial dermatitis with numerous eosinophils,” the authors noted. After ruling out bullous pemphigoid, the patient was diagnosed with exaggerated response to insect bites in the setting of CLL.

At first, the patient was given oral antihistamines and betamethasone ointment for flares, but Guo and colleagues said those therapies were ineffective. He was then prescribed a tapered course of prednisone, which resolved his lesions but was not considered a sustainable solution due to the frequency of his flares. Oral dapsone was tried, but had no effect.

After 2 years of treatment, the authors said the patient’s CLL was stable, but he continued to have intense reactions to insect bites.

“Patient was subsequently started on rituximab (Rituxan; Genentech/Biogen) infusions with hematology, which also did not affect disease activity,” the authors said. “IVIG [intravenous immunoglobulin] infusions were also attempted with hematology that helped the patient’s anemia but did not affect his cutaneous disease.”

That led doctors to turn to the biologic dupilumab, beginning with a loading dose of 600 mg and then 300-mg doses every 2 weeks. A month later, the patient said he believed his reactions were less severe and were healing faster. By 4 months, the patient said he had not had an adverse reaction in more than a month and that his previous areas of reaction had healed. The decision was made to continue the patient on ongoing 300-mg doses of dupilumab every month. As of the case report’s writing, he had not experienced a recurrence of the skin reactions.

Guo and colleagues said this is the first reported case of the successful treatment of exaggerated response to insect bites in CLL using dupilumab.

“The exaggerated response to insect bites does not always correlate with disease activity of CLL, and in some cases will actually precede diagnosis of CLL,” the authors said. “Our patient had quiescent CLL but still had an exaggerated response to insect bites.”

The investigators believe the exaggerated response was likely due to neoplastic B cells causing increased production of IL-4 and IL-5. Dupilumab binds to the alpha subunit receptor of IL-4, they said, inhibiting the signaling pathways of both IL-4 and IL-13.

“By blocking IL-4 and IL-13, dupilumab is likely able to reduce the inflammatory process and decrease the recruitment of eosinophils to the skin lesion,” they wrote.

Guo and colleagues concluded that their case shows the potential of dupilumab in the setting of CLL, even when the dosage is decreased to 300 mg per month.

Reference

Guo W, Miller D, Manci R, Korzenko A. A case of dupilumab used to treat the exaggerated response to insect bites in the setting of chronic lymphocytic leukemia. JAAD Case Rep. 2024;45:56-58. Published January 17, 2024. doi:10.1016/j.jdcr.2024.01.003