Acneiform eruption induced by cetuximab.

Cetuximab is a recombinant human/mouse chimeric monoclonal antibody that targets the extracellular domain of the epidermal growth factor receptor (EGFR). Cetuximab is approved by the US Food and Drug Administration for the treatment of EGFR-expressing metastatic colorectal cancer as monotherapy in patients who are intolerant to irinotecan-based chemotherapy, or in combination with irinotecan in patients who are refractory to irinotecan-based chemotherapy. Due to the important role of the EGFR in skin homeostasis, cutaneous reactions are a common adverse effect of cetuximab, mainly as acneiform follicular eruption seen in almost 85% of patients. We report on a 46-year-old female Caucasian patient with metastatic colorectal cancer, referred to our department for acneiform eruption induced by cetuximab in combination with irinotecan. Four days after the first infusion the patient developed intense acneiform eruption consisting of erythematous follicular papules and pustules spread to the face, neck and upper part of the trunk, accompanied by intense pruritus and fever (38.0 degrees C). There were no comedones. Biopsy specimen revealed superficial and florid neutrophilic suppurative folliculitis. She was treated with erythromycin tablet 600 mg, three times a day for 1 month, and topical clindamycin solution 3%. After 1 month of treatment, the lesions consistently faded, and the patient continued receiving immunochemotherapy.