Haemangioma and Vascular Birthmarks

Introduction

Vascular birthmarks are common, present in a substantial minority of newborns in some form, and range from trivial marks that fade on their own to lesions that threaten vision, airway or cardiac function. They span two entirely different underlying processes - abnormal cellular proliferation in the case of vascular tumours, and a structural error in vessel formation in the case of malformations - and telling the two apart from the history and examination alone is usually possible without any imaging at all. The single most important organising idea, and the one most heavily tested, is the distinction between vascular tumours, which proliferate and then involute, and vascular malformations, which are structural anomalies present from birth that persist and grow proportionately with the child.¹

This distinction predicts natural history, guides which lesions need active treatment versus reassurance, and determines which associated syndromes need to be screened for - getting it right in the first consultation shapes everything that follows.²

Infantile haemangioma

Infantile haemangioma is the commonest vascular tumour of infancy, more frequent in girls, preterm and low-birthweight infants. It is often absent or barely visible at birth, appearing as a faint red mark or area of pallor, then becoming clinically obvious over the first few weeks of life.

Natural history

Management

Most infantile haemangiomas are small, uncomplicated, and need nothing beyond parental reassurance and photographic monitoring, since spontaneous involution is the expected outcome. Active treatment is reserved for lesions that threaten function or carry a high risk of permanent disfigurement.

Parental anxiety is often significant, particularly during the proliferative phase when a lesion is visibly growing week to week and can attract unwanted attention or comments from strangers. Clear counselling on the expected natural history - rapid growth, then a plateau, then years of slow fading - alongside honest discussion of when active treatment is and is not indicated, does much to reduce distress even when no treatment is needed.

• Oral propranolol is first-line for a haemangioma threatening vision (periorbital), airway (subglottic), causing ulceration, or at high risk of significant cosmetic harm (large facial lesions) - it works by promoting vasoconstriction and inhibiting the angiogenic drivers of proliferation, and is most effective when started during the proliferative phase
• Topical timolol (a beta-blocker) is used for small, thin, superficial haemangiomas not requiring systemic treatment
• Pulsed dye laser can help residual telangiectasia or ulceration, though it has a limited role in the proliferative phase itself
• Surgery is reserved for lesions causing functional compromise unresponsive to medical treatment, or for residual fibrofatty tissue or skin changes after involution

Other vascular tumours: Kaposiform haemangioendothelioma

A rarer, more aggressive vascular tumour, kaposiform haemangioendothelioma (and the related tufted angioma) is important to distinguish from a straightforward infantile haemangioma because it carries a specific, dangerous complication: Kasabach-Merritt phenomenon, a consumptive coagulopathy with severe thrombocytopenia caused by platelets being trapped and destroyed within the abnormal vascular tumour. It presents as a rapidly enlarging, firm, purpuric lesion, often with bruising, and needs urgent specialist assessment and treatment, since the coagulopathy itself can be life-threatening.

Congenital haemangioma

Unlike infantile haemangioma, a congenital haemangioma is fully formed at birth, having completed its proliferation in utero, and does not show the typical postnatal growth phase. Two subtypes are recognised: rapidly involuting congenital haemangioma (RICH), which regresses substantially within the first year, and non-involuting congenital haemangioma (NICH), which persists unchanged and may need surgical excision if problematic.

Vascular malformations

Vascular malformations are structural abnormalities of blood or lymphatic vessels, present at birth (even if not always immediately visible), that grow proportionately with the child rather than proliferating and involuting. They are classified by the type of vessel predominantly involved.

Capillary malformation (port wine stain)

A flat, pink-to-purple patch present at birth, most often on the face, that persists lifelong, darkening and sometimes thickening with age if untreated. Pulsed dye laser is the mainstay of treatment, most effective when started early.

Venous malformation

A soft, compressible, bluish swelling that enlarges with dependency, crying, or Valsalva manoeuvre, reflecting its low-flow venous origin. It can cause pain, particularly from thrombosis within the malformation (producing palpable phleboliths), and may need imaging (MRI) to define its extent before treatment, which ranges from compression garments to sclerotherapy or surgery.

Lymphatic malformation

Classified as macrocystic or microcystic, presenting as a soft tissue swelling that can be transilluminable when macrocystic. It carries a significant risk of infection and of sudden enlargement following intralesional bleeding or infection, and management (sclerotherapy or surgery) is guided by symptoms and cosmetic impact.

Arteriovenous malformation

A high-flow lesion with direct arteriovenous shunting, warm to touch, often with a palpable thrill or audible bruit, that characteristically enlarges at puberty or after trauma rather than remaining static. Large lesions can cause high-output cardiac failure, and management is complex, typically combining embolisation with surgical resection under specialist vascular anomaly service input.

Differential diagnosis and common mimics

• Salmon patch (stork mark, 'angel kiss') - a common, flat, pink patch on the eyelids, glabella or nape of the neck, present in a large proportion of newborns, that fades over the first year or two and needs no treatment or investigation
• Mongolian blue spot (dermal melanocytosis) - a blue-grey patch, usually over the lower back or buttocks, caused by dermal melanocytes rather than blood vessels; benign and fades over childhood, but worth documenting clearly since it can otherwise be mistaken for bruising and raise unnecessary safeguarding concern
• Pyogenic granuloma - a rapidly growing, friable, bleeding vascular lesion that arises later in childhood or adulthood (unlike the birthmarks above), often after minor trauma

Investigations

Most vascular birthmarks are diagnosed clinically from appearance and history (present at birth versus appearing afterwards; static versus proportionately growing versus proliferating then involuting).

• Ultrasound with Doppler - a useful first-line imaging test to characterise flow (high versus low) and extent
• MRI - defines deep or extensive malformations, particularly before intervention, and assesses for associated structural anomalies (for example spinal dysraphism, PHACE-associated brain and vascular findings)
• Echocardiography - screens for cardiac anomalies in suspected PHACE syndrome or for high-output failure in a large arteriovenous malformation
• Genetic testing - considered where a specific overgrowth or malformation syndrome is suspected

Red flags

Prognosis

Infantile haemangiomas have a favourable natural history, with the large majority involuting substantially by mid-childhood, though some leave residual skin changes needing later cosmetic management. Vascular malformations, by contrast, are lifelong structural anomalies that do not regress, and their long-term outlook depends on type, extent and how early appropriate treatment (laser, sclerotherapy, embolisation or surgery) is started - which is why accurate early classification matters well beyond the neonatal period.