TABLE 1.

Risk level of IHs of varying types

Risk level	Clinical examples and reason(s) for concern
Highest	Large (>5 cm) or segmental facial or scalp: higher risk of airway hemangiomas (if beard area), may be associated with PHACE syndrome, high risk of scarring and/or disfigurement. Large or segmental lumbosacral or perineal: may be associated with LUMBAR syndrome, high risk of ulceration and scarring. Multifocal IHs (≥5) and abdominal ultrasonography reveals hemangiomas: may be associated with abdominal compartment syndrome, high‐output congestive heart failure, and hypothyroidism. Periocular IH causing eyelid asymmetry, lid closure or ptosis, proptosis, or other findings with potential impact on visual axis: risk of astigmatism, anisometropia, and amblyopia
High	Large segmental IH on trunk or extremities: risk of scarring and/or disfigurement. Any facial IH ≥ 2 cm (> 1 cm if ≤ 3 mo of age): high risk of scarring and/or disfigurement. Nasal tip or lip IH even if < 1 cm: high risk of scarring and/or permanent distortion of anatomic landmarks. Oral risk of ulceration or bleeding, may interfere with feeding. Neck or scalp IH > 2 cm during growth phase: risk of ulceration (neck), risk of ulceration, scarring, and/or hair loss (scalp). Breast: risk of permanent changes in breast development (eg, breast asymmetry) or nipple contour. Ulcerated hemangioma (any site): risk of severe pain, scarring and/or disfigurement, and bleeding.
Intermediate	Perineal IH (localized) without ulceration: potential for ulceration in this location. Trunk of extremity IH > 2 cm especially in growth phase or if abrupt transition from normal to affected skin (ie, ledge effect): risk of scarring and/or disfigurement.
Low	IH < 2 cm on trunk of extremities in areas easily covered by clothing. IH on trunk of extremities > 2 cm if gradual transition from normal to affected skin.

(Reprinted with permission from Ref. 1).