These common malformations, present in about 50% of all babies, are caused by dilatated capillaries in the superficial dermis. They are dull red, often telangiec-tatic macules, most commonly on the nape of the neck (‘erythema nuchae’), the forehead and the upper eyelids. Nuchal lesions may remain unchanged, but patches in other areas usually disappear within a year.
These are also present at birth and are caused by dilatated dermal capillaries. They are pale, pink to purple macules, and vary from the barely noticeable to the grossly disfiguring. Most occur on the face or trunk. They persist, and in middle age may darken and become studded with angiomatous nodules (Fig. 18.49). Occasionally a port-wine stain of the trigeminal area (Fig. 18.50) is associated with a vascu-lar malformation of the leptomeninges on the same side, which may cause epilepsy or hemiparesis (the Sturge–Weber syndrome), or with glaucoma.
Excellent results have been obtained with careful aand time-consumingatreatment with a 585-nm flashlamp-pumped pulsed dye laser. Treat-ment sessions can begin in babies and anaesthesia is not always necessary. If a trial patch is satisfactory, 40–50 pulses can be delivered in a session and the procedure can be repeated at 3-monthly intervals. On the other hand, some adults become very adept at using cosmetic camouflage (see Fig. 1.6).
A large port-wine stain of a limb may be associated with overgrowth of all the soft tissues of that limb with or without bony hypertrophy. There may be underlying venous malformations (Klippel–Trenaunay syndrome), arteriovenous fistulae (Parkes Weber syn-drome) or mixed venous–lymphatic malformations.