Infantile Hemangioma

An infantile hemangioma (IH) is a benign vascular tumour of infancy arising from abnormal proliferation of endothelial cells that stain positive for GLUT1 (erythrocyte-type glucose transporter protein) — a distinguishing immunohistochemical marker not present in other benign vascular tumours and, critically, not present in vascular malformations, the other major category of "birthmark" that IH is frequently confused with.^[1] IH is the single most common benign tumour of infancy, affecting an estimated 4-10% of infants overall, with the more precise and commonly cited figure — the working estimate this chapter uses — closer to 4-5%.^[2][1]

Most IH are small, innocuous, and need no treatment beyond reassurance and watchful waiting: the defining natural history of an IH is a period of rapid growth followed by spontaneous regression, and the large majority of lesions never threaten function, cause meaningful pain, or leave a lasting cosmetic trace. But up to 15% of IH develop a genuine complication — ulceration, pain, functional impairment, or a real risk of permanent disfigurement — and this minority is what this chapter is built around.^[2] For those infants, oral propranolol is now the guideline-endorsed, first-line treatment, having displaced systemic corticosteroids as the standard of care over the past decade and a half on the strength of a substantially better efficacy and safety profile.^[1][3] Timing matters here more than in almost any other chapter in this library: because the most rapid IH growth happens in the first few months of life, the practical window to intervene before growth — and any resulting damage — is complete is genuinely narrow, and recognizing a high-risk IH early, ideally within the first month or two of life, is one of the single most consequential things a pharmacist or primary care clinician can do for these patients.^[1][2]

The growth cycle — why timing is the whole story

Unlike most conditions in this library, IH follows a genuinely predictable, well-characterized three-phase natural history, and where a given lesion sits on that timeline is often more clinically important than its size or appearance on any single visit.

What a classic IH looks like at each stage

A classic superficial ("strawberry") infantile hemangioma in the proliferative phase — raised, lobulated, and bright red. (Zeimusu, public domain, Wikimedia Commons)

An infantile hemangioma in the involuting phase — still a raised vascular lesion, but with the softening and colour change that mark the transition out of active proliferation. (Gstk, CC BY-SA 4.0, Wikimedia Commons)

A flat infantile hemangioma later in involution, illustrating the gradual flattening and colour fading that most lesions undergo over the following years. (Gstk, CC BY-SA 4.0, Wikimedia Commons)

Classification — depth and anatomic pattern

IH are also classified by anatomic pattern, and this distinction genuinely matters for risk: a localized/focal IH is a well-defined lesion that appears to arise from a single central point, while a segmental IH covers a broader anatomic territory — often plaque-like, frequently more than 5 cm in diameter, and arising across one or more developmental units. Segmental IH, and especially large segmental facial IH, carry meaningfully higher risk of ulceration, disfigurement, and an associated structural anomaly (PHACE or LUMBAR syndrome — see Assessment/Diagnosis and Special Populations) than a comparably sized focal lesion.^[1] Indeterminate (partial segmental) IH fall between these two patterns, and multifocal IH — 5 or more discrete lesions at separate sites — raise a specific concern for hepatic and other visceral hemangiomas (see Assessment/Diagnosis).^[1]

Who develops IH

• Female sex — IH occur more often in girls than boys.^[1]
• Multiple gestation (twins).^[1]
• Prematurity and low birth weight — risk rises sharply as birth weight falls; as many as 30% of infants born weighing under 1 kg develop an IH.^[1]
• White race/ethnicity, relative to other groups.^[1]
• A family history of IH is reported anecdotally, though the genetics remain incompletely defined. The leading pathogenetic hypothesis involves circulating endothelial progenitor cells migrating to sites where local conditions (hypoxia, developmental field disturbances) favour their proliferation, but the underlying cause is not yet fully established.^[1]

Why some IH become high risk

The great majority of IH are none of the following — but up to about 1 in 6 or 1 in 7 IH develops a genuine complication, and recognizing which lesions are more likely to fall into that group is the entire purpose of the risk-stratification framework covered in Assessment/Diagnosis.^[2] The clinical findings that push an IH into the high-risk category are not about a lesion being "bad" in a vague sense — each maps to a specific, named risk: a life-threatening complication (airway or hepatic involvement), functional impairment (vision, feeding), ulceration, an associated structural anomaly (PHACE, LUMBAR), or a genuine risk of permanent disfigurement.^[1]

Diagnosis is clinical

IH is diagnosed clinically in the overwhelming majority of cases, based on the characteristic appearance and — just as importantly — the characteristic growth trajectory described above. A lesion that is absent or barely visible at birth and then grows rapidly over the first weeks to months of life is behaving like an IH in a way that a vascular malformation (present at birth, growing proportionately with the child, never truly regressing) and a congenital hemangioma (fully formed at birth) do not.^[1]

The key differential: IH vs. congenital hemangioma vs. vascular malformation

A congenital hemangioma is fully developed at birth — unlike a true IH, which is often minimal or absent at birth and grows postnatally — and is GLUT1-negative; it does not respond to propranolol or corticosteroids and follows one of three distinct patterns: rapidly involuting (RICH, which typically regresses on its own within the first 1-2 years and rarely needs treatment), non-involuting (NICH, which persists unchanged and may need surgical excision), or partially involuting (PICH).^[2] A vascular malformation (for example a port-wine stain/capillary malformation) is also present at birth, grows proportionately with the child rather than in IH's distinctive rapid-then-regressing pattern, and never truly involutes on its own.^[1]

When to image

Most IH do not need imaging at all — reserve it for genuine diagnostic uncertainty rather than ordering it reflexively.

• Do not image unless the diagnosis is uncertain, there are 5 or more cutaneous IH, or an associated structural anomaly is suspected.^[1]
• Ultrasound (with Doppler) is the initial imaging modality of choice when the diagnosis is uncertain — no sedation, no ionizing radiation; most IH appear as a well-defined, high-flow mass without arteriovenous shunting (an important exception: hepatic IH can show arteriovenous shunting).^[1] Abdominal ultrasonography (roughly 95% sensitivity for hepatic IH) is specifically recommended to screen for hepatic involvement in any infant with 5 or more cutaneous IH.^[1]
• MRI (± MRA of the head and neck, and echocardiography including the aortic arch) is indicated when there is concern for an associated structural anomaly — PHACE or LUMBAR syndrome — most often triggered by a large (over 5 cm) segmental facial/scalp IH or a segmental lumbosacral/perineal/gluteal IH. This work-up should be completed before, or very shortly after, starting propranolol in this specific group, not deferred.^[1][4][3]
• CT is not the modality of choice for IH given the ionizing radiation involved, particularly in young infants.^[1]

Risk stratification — the framework that drives every treatment decision

Classify every IH as high-risk if there is evidence of, or potential for, any of the following.^[1]

^[1]

PHACE and LUMBAR syndrome — a brief orientation

PHACE syndrome (Posterior fossa malformations, segmental facial Hemangioma, Arterial anomalies, Cardiac anomalies/aortic coarctation, and Eye anomalies, ± sternal defects — "PHACES") is diagnosed by consensus criteria: a head/scalp hemangioma over 5 cm in diameter plus 1 major or 2 minor criteria, or a hemangioma of the neck, upper trunk, or proximal upper extremity plus 2 major criteria, drawn from cerebrovascular, cardiovascular, ocular, and ventral/midline-defect categories.^[4] LUMBAR syndrome is its lower-body counterpart — Lower body IH with Urogenital anomalies and/or Ulceration, Myelopathy, Bony deformities, Anorectal malformations and arterial anomalies, and Renal anomalies — associated with a segmental IH of the lumbosacral, gluteal, or perineal area.^[1] See Special Populations for the specific screening work-up.

• Correctly distinguish the large majority of IH that need only observation and parent education from the minority that need active treatment, using the risk-stratification framework above rather than gestalt.
• For high-risk IH, intervene during the proliferative phase — the window in which treatment most effectively limits ultimate size and prevents complications — rather than waiting to "see how it grows."^[1]
• Arrest proliferative growth and accelerate involution with first-line pharmacotherapy.^[1][3]
• Prevent and manage the specific complications that drive most of this chapter's morbidity: ulceration, and functional impairment from a high-risk location (airway, periocular, oral).^[1]
• Screen appropriately for PHACE/LUMBAR syndrome and hepatic involvement before committing to systemic therapy in the specific groups at risk.^[4][1]
• Minimize long-term cosmetic sequelae, recognizing that roughly half of untreated IH leave some residual skin change behind.^[2]
• Use propranolol safely — real cardiovascular and metabolic risk exists, especially with the first dose and each dose increase — rather than either avoiding an indicated, guideline-endorsed treatment out of excess caution, or underestimating its monitoring requirements.^[3]
• Set families up for a safe course: feeding-timed dosing, hold-dose instructions for illness/poor intake, and a clear plan for the eventual taper/stop and rebound-growth risk.^[3][1]

• Watchful waiting with parent education is genuinely the correct treatment for the majority of IH — small, low-risk-location, uncomplicated lesions do not need pharmacotherapy, and setting expectations for the proliferative-plateau-involuting course (including that roughly half of untreated lesions leave some residual skin change) is itself a meaningful intervention.^[1][2]
• Wound care for an ulcerated IH — gentle cleansing, a non-adherent barrier dressing, and topical or, for pain, systemic analgesia — is first-line for a mild ulceration; escalate to systemic propranolol specifically when simple wound care fails or the ulcer is painful, per the Hemangiol indication itself.^[3]
• Compression or cosmetic camouflage can be a reasonable adjunct or bridge for families managing the visible impact of a lesion during the proliferative phase while a treatment decision is being made, though this is supportive rather than disease-modifying.
• Surgery and/or laser treatment (pulsed-dye laser for residual telangiectasia/erythema; surgical excision for fibrofatty residue or redundant skin) are most useful once involution is complete, and are occasionally reasonable earlier in select IH.^[1]
• Psychosocial support for parents matters in its own right — the visible, sometimes rapidly changing nature of a facial IH during proliferation is genuinely distressing for many families, independent of the lesion's actual medical risk, and acknowledging that distress is part of good care.

PHACE syndrome

PHACE syndrome should be screened for before starting propranolol in any infant with a large (generally over 5 cm) segmental facial or scalp IH — work-up includes MRI and MRA of the head and neck (including the aortic arch and brachiocephalic vessels) and echocardiography, with specialist advice sought before treatment.^[3][4] The diagnosis is made against consensus criteria drawn from cerebrovascular (posterior fossa anomalies, arterial anomalies such as dysplasia or an aberrant origin), cardiovascular (aortic arch anomalies including coarctation), ocular, and ventral/midline-defect (sternal defects, supraumbilical raphe) categories — a head/scalp hemangioma over 5 cm plus 1 major or 2 minor criteria, or a hemangioma of the neck/upper trunk/proximal upper extremity plus 2 major criteria.^[4] This screening matters clinically, not just diagnostically: propranolol lowers blood pressure and can theoretically increase stroke risk in a PHACE-syndrome infant with a significant cerebrovascular arteriopathy by reducing flow through an already narrowed or occluded vessel, so confirming the vascular anatomy first — and titrating more slowly and cautiously if therapy proceeds — is a genuine safety step, not a formality.^[3][2]

LUMBAR syndrome

A segmental IH of the lumbosacral, gluteal, or perineal area raises the analogous concern for LUMBAR syndrome; screening (spinal ultrasound for a corrected age under 6 months, or MRI, plus renal/pelvic imaging) should be considered, particularly if markers of spinal dysraphism (a sacral dimple, skin appendage, tuft of hair, or lipoma) are also present.^[1]

Hepatic and multifocal IH

Hepatic hemangiomas occur in 3 patterns — focal, multifocal, and diffuse. Most multifocal hepatic IH are asymptomatic and need no treatment, but a minority are associated with high-flow macrovascular shunting that can, rarely, cause high-output cardiac failure; the rare diffuse pattern carries the greatest risk of morbidity, typically presenting before 4 months of age with severe hepatomegaly and a risk of abdominal compartment syndrome and a consumptive hypothyroidism from type 3 iodothyronine deiodinase activity within the IH tissue.^[1] Screening abdominal ultrasonography is recommended for any infant with 5 or more cutaneous IH, since the risk of liver involvement rises meaningfully in this group.^[1]

Prematurity and low birth weight

Propranolol is contraindicated in a premature infant who has not yet reached 5 weeks of corrected age, and in any infant weighing under 2.5 kg; the age window for starting therapy is corrected for prematurity throughout.^[3] A more cautious, slower dose titration is reasonable in a neonate or an infant under 2 months corrected age.^[2]

Pregnancy and breastfeeding

Hemangiol is not intended to be prescribed to pregnant or nursing women — it is an infant-specific formulation, and propranolol treatment has been associated with embryotoxicity in animal studies.^[3] Propranolol does pass into breast milk; if an infant being treated with Hemangiol is also breastfed, confirm the mother is not taking a medication that is itself contraindicated with propranolol, since that combination is a specific contraindication to continuing Hemangiol therapy in the infant.^[3]

Renal impairment

Hemangiol has not been studied in infants with impaired renal function and is not recommended in this population in the absence of data; propranolol and its metabolites are renally excreted, and adult data show 3- to 6-fold higher peak concentrations and decreased clearance in dialysis and chronic renal failure, respectively.^[3]

Hepatic impairment

Hemangiol has not been studied in infants with impaired hepatic function and is not recommended in this population in the absence of data; propranolol is hepatically metabolized, and adult cirrhosis data show roughly 3-fold higher steady-state concentrations and a longer terminal half-life (about 11 hours versus 4 hours) compared with healthy subjects.^[3]

Peri-operative considerations

Beta-blockers can interact with anesthetic agents, blunting reflex tachycardia and increasing hypotension risk; hold propranolol at least 48 hours before any procedure requiring anesthesia, and alert the anesthetist that the infant is being treated with a beta-blocker.^[3]

• Monthly clinical review and weight-based dose re-adjustment throughout the propranolol course.^[3]
• Set realistic expectations for response timing: an initial response is typically seen within 3-4 weeks, though a visible colour change is often noted within the first 48 hours of starting treatment.^[2]
• Confirm caregivers can recognize the atypical, masked infant presentation of hypoglycemia (irritability, lethargy, unusual sleepiness, nightmares or crying out during sleep) rather than expecting the classic adult adrenergic picture that propranolol itself blunts.^[3]
• Confirm the feeding-timed dosing routine (with/after feeds, second dose in late afternoon, hold for vomiting/poor intake, same caregiver handles medication and feed) is genuinely being followed at each visit, not just explained once at the start.^[3]
• Track objective growth or regression of the lesion — consistent, comparably lit photographs at each visit are a practical way to confirm response and to catch a genuine non-responder early rather than late.
• At the end of a course, counsel explicitly on rebound-growth risk (roughly 10-25%, highest if stopped before 12 months of age) and arrange a specific follow-up visit rather than leaving re-evaluation to chance.^[1]
• For a patient on oral or intralesional corticosteroid therapy, monitor growth parameters, blood pressure, and for signs of infection or mood change over the treatment course.^[1]
• Educate every caregiver, regardless of the treatment chosen, about the expected natural history of IH and its potential for causing complications or disfigurement — this is a Key Action Statement in its own right, not an afterthought once a prescription is written.^[1]

1. No improvement at all within the first 2 months of oral propranolol at an adequate dose: this is a genuine treatment failure per Canadian labelling — reassess the diagnosis, confirm adherence and dosing, and check whether a comorbidity (or a dose reduction made for another reason) has kept the dose below target, rather than simply continuing unchanged.^[3]
2. Propranolol-associated bronchospasm with a lower respiratory tract infection: interrupt therapy; only consider re-starting once the infant has fully recovered, confirmed by a full clinical exam including auscultation; permanently discontinue if bronchospasm recurs, or if isolated bronchospasm or asthma is diagnosed.^[3]
3. Rebound growth after stopping, or during a taper: re-initiate propranolol under the same monitoring conditions as the original start, rather than assuming the treatment window has passed.^[3][1]
4. An ulcerated IH not responding to propranolol plus simple wound care: reassess for infection, escalate wound care, and consider pain control; an ulcer that continues to fail therapy warrants hemangioma-specialist reassessment rather than an indefinite trial of the same regimen.
5. A genuine propranolol contraindication (true asthma/reactive bronchospasm history, symptomatic bradycardia, heart block) or a poor/inadequate response despite adequate dosing and duration: move to oral or intralesional corticosteroid therapy as above, rather than persisting with an ineffective or unsafe propranolol course.^[1]
6. Significant residual skin change once involution is complete, or substantially complete: refer for consideration of surgery and/or laser treatment rather than continuing to "wait and see" indefinitely.^[1]

• Treating every IH with propranolol regardless of risk — most IH are low-risk and genuinely need only observation and parent education; pharmacotherapy is for the high-risk minority.^[1][2]
• Waiting to see how a high-risk IH "does" before referring, rather than referring promptly (ideally by 1 month of age) — the treatment window is tied to the proliferative phase, and a delayed start is a genuinely less effective start.^[1]
• Starting or increasing propranolol without the required in-clinic monitoring window (heart rate/blood pressure at least hourly for at least 2 hours) after the first dose and every dose increase.^[3]
• Missing the atypical, masked presentation of infant hypoglycemia on propranolol because it does not look like the adult adrenergic picture (tachycardia, shakiness) that propranolol itself blunts.^[3]
• Dosing propranolol without regard to feeds, or scheduling the second daily dose late enough at night that a hypoglycemic episode would go unnoticed during sleep.^[3]
• Assuming a beard-distribution or anterior-neck IH with stridor is croup or reactive airway disease rather than considering an airway IH.^[1]
• Starting propranolol in a large segmental facial IH without completing PHACE screening first — a significant cerebrovascular anomaly in PHACE syndrome can make the blood-pressure-lowering effect of propranolol genuinely dangerous.^[3][4]
• Reaching for topical timolol as a substitute for oral propranolol once a high-risk feature (ulceration, a high-risk location, a large/deep lesion) is present — it is a reasonable option only for low-risk, thin, superficial IH.^[1]
• Stopping propranolol abruptly at exactly 6 months in a still-actively-growing lesion, and failing to counsel on rebound-growth risk, particularly if therapy stops before 12 months of age.^[1]
• Continuing an ineffective propranolol course past 2 months with no improvement at all, rather than recognizing this as a defined treatment failure.^[3]

Oral Propranolol — First-Line Systemic Therapy (Hemangiol, Health Canada)

The complete 3-week weight-based titration schedule; give twice daily, at least 9 hours apart, during or immediately after a feed.

Topical and Second-Line Systemic/Intralesional Therapy

Reserved for low-risk lesions (topical timolol) or for when propranolol is contraindicated, not tolerated, or inadequately effective.