Can topical beta-blockers reduce the size of superficial infantile hemangiomas of the head and neck?

BACKGROUND The serendipitous discovery of propranolol as a medical therapy for infantile hemangioma in 2008 resulted in a significant change in the treatment paradigm for patients with hemangioma. The use of systemic propranolol is now widely used, either alone or in conjunction with other medications or surgical treatments. Although generally well tolerated, propranolol is typically initiated with observed monitoring of vitals on either an inpatient or outpatient manner due to the risk of adverse events. It is prescribed as a liquid formulation in three doses daily. The most common side effects include hypoglycemia and bradycardia. The use of a topical betablocker was initiated soon after systemic treatment was discovered, with the intention of reducing systemic side effects. An ophthalmic formulation of timolol for elevated intraocular pressure was already available. The formulations are timolol maleate 0.1% and timolol 0.5% gelforming solution. Ocular administration of timolol maleate 0.1% results in high levels of systemic absorption and can cause bradycardia, but this is reduced significantly with use of the 0.5% gel-forming solution. Absorption is likely even less so when applied to the dermis instead of the eye. A formulation of 1% topical propranolol ointment is also available; it is less studied, but reports indicate that it has similar results as topical timolol. The indications for topical therapy are not clearly defined, yet systemic therapy has consensus indications: patients with advanced hemangioma causing functional deficits such as those located adjacent to orbit or in airway, and for those causing significant cosmetic deformity or ulceration. The effectiveness and indications for topical beta-blocker therapy had not been thoroughly studied until recently.