AUTHOR‘S RESPONSE

We were most interested to hear the opinions of the Harvard team regarding the diagnosis of the patient we presented. Whilst their suggested diagnosis of linear epidermal naevus with a related syndrome is an interesting postulation, it is unlikely. We treat a significant number of linear epidermal naevi in our unit with success using the carbon dioxide laser. In our experience, the very extensive epidermal naevi extend from head to toe in streak pattern, and do not appear in this dermatomal/semi-dermatomal pattern with a midline cut-off and as a solid block. Pathognomically, linear naevi extend along the lines of Blaschko, which almost precludes this diagnosis in our patient. Systematised linear naevi can be in a solid block (but typically are still patchy), and only in cases of very large or sub-total body surface area. The lesion in our patient was almost certainly a capillary malformation. Linear naevi in darker skin types tend to remain dark without a purple hue such as seen here. Capillary malformations also classically affect the face and nape of the neck, as in this case. Whilst we may never be certain, speculating is part of the fun, and we extend our thanks for contributing to this interesting case.