Epidermal growth factor receptor (EGFR) inhibitor induced purpuric drug eruption: Three case reports

INTRODUCTION: Purpuric drug eruption (PDE) is an uncommon, clinically distinct side effect of epidermal growth factor receptor (EGFR) inhibitors. PATIENT CONCERNS: Unlike acneiform eruption, which arises from hair follicles mainly in the head and neck area, PDE starts from xerosis cutis, primarily in the lower extremities and is not associated with hair follicles. Herein, we report 3 cases of 3 patients who had received EGFR inhibitor and were hospitalized for PDE later. The cases were characterized by painful late-onset palpable purpura with identifiable bacterial pathogens. DIAGNOSIS: The patients were diagnosed with characteristic clinical presentations, that is, late onset, PDE locations mainly in the lower extremities, nonfollicular centricity, and laboratory findings with identifiable bacterial pathogens. INTERVENTIONS: Systemic antibiotics and intensive moisturizer application were prescribed. OUTCOMES: All the patients were successfully treated within 6 to 9 days without discontinuation of EGFR inhibitors. CONCLUSION: Systemic antibiotics, topical emollient, and skin barrier repair should be included in the treatment regimens for PDE.