What is the most likely diagnosis and first-line management for a 4‑month‑old infant with a rapidly enlarging bright‑red raised lesion on the scalp?

Infantile Hemangioma: Diagnosis and Management

Most Likely Diagnosis

This is an infantile hemangioma, the most common benign vascular tumor of infancy, and oral propranolol at 2-3 mg/kg/day divided into three doses is the first-line treatment. 1

Clinical Diagnosis

The diagnosis is made clinically based on the characteristic presentation:

• Timing of appearance: Infantile hemangiomas typically appear within the first 4 weeks of life (this patient is at 4 months, within the proliferative phase) 1, 2
• Appearance: Bright red, raised lesions that are superficial appear as protuberant, bosselated, or smooth-surfaced with sharp demarcation 2
• Growth pattern: Rapid proliferation occurs between 1-6 months of age, with most growth completed by 5 months 1, 3
• Location: Scalp location is specifically mentioned as higher risk for ulceration and bleeding complications 1

Why This is High-Risk and Requires Treatment

Scalp hemangiomas are classified as high-risk and warrant early specialist referral, ideally by 1 month of age. 1, 3

The scalp location places this infant at elevated risk for:

• Ulceration: Scalp involvement is specifically identified as a high-risk site for ulceration, which can cause pain, bleeding, and permanent scarring 1
• Bleeding: Scalp hemangiomas with deep ulceration can cause profuse, even life-threatening bleeding (unlike most other locations where bleeding is minor) 1
• Disfigurement: Permanent cosmetic sequelae that are potentially life-altering, representing a paradigm shift from older "watch and wait" approaches 1

First-Line Treatment Protocol

Oral propranolol is the gold standard first-line therapy:

• Dosing: 2-3 mg/kg/day divided into three doses 1, 4, 3
• Initiation: Must be started in a clinical setting with cardiovascular monitoring every hour for the first 2 hours 1, 4
• Duration: Minimum 6 months, often continued until 12 months of age 4, 3
• Expected response: Rapid reduction in hemangioma size within 48 hours to weeks 4

Critical Timing Consideration

The most rapid hemangioma growth occurs between 5.5 and 7.5 weeks of age, much earlier than previously appreciated. 5

At 4 months of age, this infant is still within the proliferative phase (which continues up to 12 months), but the window of most rapid growth has passed. However, treatment is still indicated because:

• Scalp location carries ongoing risk of ulceration and bleeding 1
• The lesion is still actively growing (proliferative phase extends to 9-12 months) 2
• Early treatment prevents permanent disfigurement and complications 1

Alternative Therapies (If Propranolol Cannot Be Used)

• Topical timolol: May be considered for small, thin, superficial hemangiomas, applied as 1-2 drops of 0.5% gel-forming ophthalmic solution twice daily 4, 3
• Systemic corticosteroids: Prednisolone or prednisone at 2-3 mg/kg/day as a single morning dose when propranolol is contraindicated or ineffective 4

Imaging is NOT Routinely Required

Most infantile hemangiomas are diagnosed clinically without imaging. 1, 6

Imaging is reserved for:

• Atypical features in superficial lesions 1
• Deep lesions difficult to assess physically 1
• Segmental facial hemangiomas >5 cm (to evaluate for PHACE syndrome) 1
• Multiple hemangiomas ≥5 in number (to screen for hepatic involvement) 1, 6

Common Pitfall to Avoid

Do not confuse infantile hemangioma with vascular malformations (such as port wine stains or lymphatic malformations). 1

Key distinguishing features:

• Infantile hemangiomas are not present at birth (though 65% have precursor lesions), appear in first weeks of life, and proliferate rapidly 1, 5
• Vascular malformations are present at birth, grow proportionally with the child, and do not involute 1
• Congenital hemangiomas (RICH/NICH) are fully grown at birth and are biologically distinct from infantile hemangiomas 1