Infantile hemangioma is the most common benign vascular tumor in infancy. Oral propranolol is the first-line systemic treatment for infantile hemangiomas requiring therapy. Although most patients respond well to propranolol, rebound growth may occur after treatment discontinuation, and some patients may require restarting propranolol or receiving additional treatment. In clinical practice, propranolol may be discontinued abruptly after the lesion meets discontinuation criteria, or gradually tapered over several weeks before complete discontinuation. However, high-quality randomized evidence comparing these two discontinuation strategies remains limited.

This multicenter randomized noninferiority trial aims to compare the risk of rebound growth after abrupt discontinuation versus gradual tapering of propranolol in patients with infantile hemangioma who have received oral propranolol for at least 6 months and meet predefined discontinuation criteria.

This is a prospective, multicenter, randomized, parallel-group, noninferiority trial designed to evaluate whether abrupt discontinuation of propranolol is noninferior to gradual tapering with respect to rebound growth in infantile hemangioma.

Eligible participants will be patients clinically diagnosed with infantile hemangioma who have received oral propranolol treatment for at least 6 months and meet predefined criteria for treatment discontinuation. The discontinuation criteria include complete or near-complete clinical regression of the lesion, no obvious blood flow on ultrasound, and maintenance of maximal regression for 3 months. Participants will be randomly assigned in a 1:1 ratio to either the abrupt discontinuation group or the gradual tapering group.

Participants in the abrupt discontinuation group will stop propranolol immediately after meeting the predefined discontinuation criteria. Participants in the gradual tapering group will receive half of the original total daily dose for the first 2 weeks, followed by one quarter of the original total daily dose for another 2 weeks, and propranolol will be discontinued in week 5.

All participants will be followed for at least 3 months after propranolol discontinuation. Demographic data, infantile hemangioma characteristics, treatment history, lesion size and color before and after treatment, rebound growth, major rebound growth, adverse events after discontinuation, age at rebound, interval from discontinuation to rebound, treatment after rebound, and parental satisfaction will be collected. Rebound growth will be assessed using standardized photographs and/or ultrasound by blinded outcome assessors.

The primary outcome is the proportion of participants with rebound growth after propranolol discontinuation. Rebound growth is defined as more than 20% regrowth in the external appearance of the infantile hemangioma, including changes in color and/or volume. Secondary outcomes include the proportion of participants with major rebound growth, age at rebound, time from discontinuation to rebound, treatment after rebound, adverse events after discontinuation, and parental satisfaction. Major rebound growth is defined as rebound growth requiring modification of oral propranolol treatment, including dose adjustment or restarting propranolol.

The planned sample size is 110 participants, with 55 participants in each group, allowing for an anticipated loss to follow-up rate.

Inclusion Criteria:

1. Children with a clinical diagnosis of infantile hemangioma.
2. Complete pretreatment clinical documentation is available, including clinical photographs and/or ultrasound findings.
3. The child has received oral propranolol for at least 6 months.
4. The infantile hemangioma meets the predefined criteria for propranolol discontinuation, defined as complete or near-complete clinical regression, no obvious residual blood flow on ultrasound, and stable maximal regression for 3 months.
5. Written informed consent is provided by a parent or legal guardian.
6. The parent or legal guardian is able and willing to complete the scheduled follow-up assessments.

Exclusion Criteria:

1. Airway or hepatic infantile hemangiomas, or other high-risk lesions for which rebound growth could rapidly compromise life or vital organ function.
2. Use of propranolol for arrhythmia, hypertension, or another cardiovascular indication.
3. A history of rebound growth after prior discontinuation of propranolol.
4. Laser therapy, sclerotherapy, surgery, systemic corticosteroids, or other systemic treatment within 3 months before randomization.
5. Severe cardiac, respiratory, hepatic, renal, metabolic, or other systemic disease that may affect participant safety or study assessment.
6. Inability to complete standardized photography, ultrasound assessment, or scheduled follow-up.

Individual participant data will not be publicly shared because the dataset includes sensitive pediatric clinical information, clinical photographs, and ultrasound data. De-identified aggregate data may be made available from the principal investigator upon reasonable request and with appropriate ethical approval.

Due to the nature of the discontinuation strategies, participants, care providers, and investigators will not be masked to group assignment. Rebound growth will be assessed using standardized photographs and/or ultrasound by outcome assessors who are masked to the assigned discontinuation strategy.