1062 Amivantamab-induced pityriasis amiantacea

Amivantamab is a novel epidermal growth factor receptor (EGFR) therapy for patients with non-small cell lung cancer (NSCLC) and exon 20 insertion mutations, which many dermatologic reactions are described, ranging from acneiform dermatitis to paronychia [1]. However, pityriasis amiantacea (PA), an inflammatory scaling reaction of the scalp, has not yet been described as adverse cutaneous amivantamab. We present case 65-year-old male who presented acute onset hyperkeratotic, yellow, adherent scale on within month first amivantamab infusion NSCLC. Exam findings were consistent PA. PA reported immunomodulatory agents such vemurafenib, TNF-α inhibitors, melphalan; however, patient had exposed these causative no prior history any scalp conditions [2]. The patient’s presentation was complicated by secondary infection, halting third cycle infusion. Superinfection resolved after course trimethoprim-sulfamethoxazole topical chlorhexidine. then treated fluocinolone 0.01% oil one week, followed alternating ketoconazole 2% pyrithione zinc 1% shampoos. At 5-week follow up, significant improvement noted, marked reduction scale. resumed 25% dose reduction. Patients this immunotherapeutic agent should be closely monitored referred dermatology when arise, timely recognition treatment initiation may prevent infections, quality-of-life impairment, interruptions in plan. 1. Park K, Haura EB, Leighl NB, et al. EGFR Exon Insertion-Mutated Non-Small-Cell Lung Cancer Progressing Platinum Chemotherapy: Results From CHRYSALIS Phase I Study. J Clin Oncol. 2021;39(30):3391-3402. 2. Bari O, Cohen PR. Pityriasis following bone marrow transplant. Cutis. 2019 Jan;103(1):46-50.