Adverse cutaneous effects of neratinib

Neratinib is a tyrosine kinase inhibitor that was FDA-approved for extended adjuvant treatment in adults with human epidermal growth factor receptors-2 (HER-2) positive breast cancer in 2017. Due to the novelty of the drug, there are no current reports in the literature of adverse cutaneous effects associated with neratinib therapy. We present a case of a woman on neratinib for HER-2 positive infiltrating ductal carcinoma of the right breast who presented to the dermatology clinic with changes to the fingernails, acne, and a rash on the face. Physical examination revealed erythema, induration, and some serum crust along the lateral nail folds of the right fourth and left third digits as well as monomorphic acneiform papules and pustules on the face. The timeline of the patient's paronychia and acneiform rash were consistent with a diagnosis of neratinib-associated skin changes. The patient was prescribed doxycycline to control the acneiform eruption. For the nails, she used mupirocin ointment as well as Listerine soaks. She experienced great improvement on this regimen at her 3-month follow-up visit. This case highlights similar cutaneous side effects to epidermal growth factor receptor (EGFR) inhibitors with a newer agent, neratinib, that have not been documented in the literature.