Localized infantile hemangiomas of the face and scalp: Predilection for the midline and periorbital and perioral skin

Background/Objectives: Infantile hemangiomas are common vascular tumors. Identifying sites of predilection may provide insight into pathogenesis. Previous studies have suggested a predilection for the boundary of facial metameres. The objective was to observe patterns of localized hemangiomas on the face and scalp, determine sites of predilection, and place these patterns in a developmental context. Methods: A retrospective review of photographic archives at 10 Hemangioma Investigator Group pediatric dermatology centers identified localized infantile hemangiomas of the face and scalp. Heat map software was used to identify areas of predilection. Dot maps were used to assess frequency, and densities of infantile hemangiomas were compared between facial units using t-testing. The scalp was divided into quintiles to assess relative frequencies. Results: Four thousand one hundred fifty-three focal face and scalp infantile hemangiomas were mapped, of which 2962 (71%) were mapped to a frontal facial template. On the face, 73.8% (2186/2962) of hemangiomas occurred along the midline axis or perpendicularly across the ocular axis in a cross-shaped area of predilection intersecting at the glabella. Scalp hemangiomas show a predilection for the midline, with 149/295 (50.5%) noted on the top of the scalp at the midline (P < 0.001). Localized hemangiomas do not demonstrate a preferential laterality. Conclusion: The distribution of localized infantile hemangiomas of the face and scalp is not random. There is preferential involvement of the midline face and scalp and the ocular axis. The regions corresponding to the boundaries between the embryonic facial segments, including the maxillary and mandibular metameres, are not accentuated in the distribution of infantile hemangiomas.