BackgroundInfantile hemangiomas (IH) are the most common soft tissue tumors of childhood. Although most of these tumors are not worrisome, some IH may be life or function-threatening, can lead to permanent disfigurement, or have associated structural congenital anomalies, requiring early recognition and referral to specialists for treatment consideration. Since 2008, oral propranolol has been widely considered to be the first-line treatment for IH.ObjectivesTo evaluate aesthetic and functional outcome in propranolol-treated infantile hemangiomas according to the age of treatment onset.MethodsRetrospective, observational study of infantile hemangioma patients under 4 years of age at the time of diagnosis, treated with oral propranolol. Evaluated parameters included: pre and post-treatment morphologic/aesthetic aspects of the hemangioma, total resolution rate, degree of functional compromise of affected areas and its evolution. Two independent pediatric dermatologists evaluated all cases reviewing clinical data from medical records and comparing clinical photographs taken at initiation and at the end of treatment of each patient. Data were analyzed with STATA 13.0 program.ResultsThe cohort included 138 patients, with a female predominance. The median age at therapy onset was 3 months. The morphological/aesthetic improvement rate was 99% (95% CI 96‒99), the total resolution rate was 48% (95% CI 44‒60) and the functional improvement rate reached 100%. When comparing total resolution outcome versus age when treatment started, the improvement was larger in younger patients (3.5 vs. 4.9 months, p = 0.01). When comparing the total resolution rate in those younger or older than 3 months at treatment initiation, the percentage of total resolution in the younger group was 57% vs. 40% in the older one (p = 0.05).Study limitationsRetrospective design; patients photographs were the sole indicators used to measure regression rates. Visual assessment is subjective.ConclusionThe present results strongly suggest that early (before 3 months of age) initiation of treatment of infantile hemangiomas with propranolol results in significantly higher aesthetic and functional improvement rates and a higher percentage of total resolution.