Inclusion Criteria:  EGFR inhibitors-induced paronychia Older than 20 years Having at least one finger or toe involved with CTCAE grade 2~3 paronychia on each of their hands or feet  Exclusion Criteria:  Indication for surgical treatment Medical history of asthma, severe COPD, sinus bradycardia, SA block, 2nd to 3rd degree AV conduction delay, heart failure, cariogenic shock or allergy to timolol