Sheftell et al have considered the differential diagnosis of Harry Potter's headache in detail.1 We would, however, like to draw their attention to one additional diagnosis which we think they have overlooked.
The striking thing about Harry Potter on physical examination is of course the “zig-zag” scar on the right side of his forehead. A unifying diagnosis that relates a scar on the forehead to migraine and other facial neuralgic pain would be linear scleroderma “en coup de sabre” (Fig.). Scleroderma “en coup de sabre” is a rare localized form of scleroderma or morphoea usually located on the forehead to one side of the midline. It is so named because of its resemblance to a scar made by the cut of a sabre, although a wand could leave a similar mark. A zig-zag pattern has not previously been described.
Scleroderma en coup de sabre and the related condition, Parry Romberg syndrome (progressive facial hemiatrophy), are known to be associated with a high frequency of migraine (52% in one study2) and facial pain. The etiology of these conditions is probably autoimmune. In boy wizards, however, it remains a possibility that the cause could be an injury from a wand in the infantile period.