RESUMO
PURPOSE: Acneiform rash is frequently observed in patients undergoing cancer treatment with anti-epidermal growth factor receptor (EGFR) antibody drugs and can often necessitate treatment discontinuation. However, the specific changes in skin parameters resulting from anti-EGFR antibody drug administration are poorly understood. Therefore, this study aimed to longitudinally and quantitatively evaluate the changes in skin parameters (transepidermal water loss [TEWL], hydration level, and sebum level) caused by anti-EGFR antibody drugs and investigate their potential as control markers for skin disorders. METHODS: This prospective study included 12 patients with colorectal cancer who received anti-EGFR antibody drugs for the first time. The assessment items included the grade of acneiform rash and skin parameters (TEWL, hydration level, and sebum level), which were observed for up to 6 weeks after administration of the medication. RESULTS: The enrolled patients were classified into two groups based on the grade of acneiform rash caused by anti-EGFR antibody drugs: "Grade 1 and lower," and "Grade 2 and higher." The skin parameters were compared between these groups. The results showed that in the "Grade 2 and higher" group, TEWL in the face (at week 2 of administration), chest (baseline, weeks 2 and 6 of administration), and back (at week 2 of administration) were significantly higher than those in the "Grade 1 and lower" group. However, the two groups showed no significant differences in hydration or sebum levels at any time point. CONCLUSION: TEWL can serve as a marker for acneiform rashes induced by anti-EGFR antibody drugs during cancer treatment.