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Diagnosis: Phakomatosis Pigmentovascularis
Figure 1. The left lower limb is longer and larger in circumference than the right limb.
Figure 2. An extensive nevus flammeus is present on the face, trunk, and right arm with a diffuse bluish discoloration of the lateral and posterior aspects of the right chest wall.
Figure 3. The pink and blue pigmentary changes involve large portions of the skin surface.
Phakomatosis pigmentovascularis (PPV) is a rare disorder characterized by the association of cutaneous vascular and melanocytic lesions. The pigmentary changes usually involve more than 50% of the skin surface and persist throughout life.1
Nevus flammeus, a constant feature in PPV, is a congenital vascular malformation consisting of dilated thin-walled capillaries and small veins. The port-wine stain of Sturge-Weber syndrome is a nevus flammeus; however, in PPV the vascular malformation is much more extensive in distribution. The most common melanocytic lesion associated with PPV is the slate gray to blue discoloration typical of Mongolian spots but more extensive in distribution. Other pigmentary changes include nevus spilus, a café-au-lait macule studded with small, dark, raised nevi; nevus pigmentosus et verrucosus, an epidermal nevus that may have raised, wartlike components; and nevus anemicus, macules or patches that are pale, reflecting vasoconstriction of underlying vessels.
Phakomatosis pigmentovascularis has been classified into 4 types: I, characterized by nevus flammeus and nevus pigmentosus et verrucosus; II, nevus flammeus and blue spots with or without nevus anemicus; III, nevus flammeus and nevus spilus with or without nevus anemicus; and IV, nevus flammeus, blue spots, and nevus spilus, with or without nevus anemicus.1 Additionally, the 4 types are divided into subtypes a and b. Subtype a has cutaneous disease only, while subtype b has cutaneous and systemic features.1
Associated systemic features
Children with PPV may have systemic features associated with Sturge-Weber and Klippel-Trenaunay syndromes. In Sturge-Weber syndrome, which almost always features a port-wine stain in the distribution of the first branch of the trigeminal nerve, associated systemic problems may include glaucoma and central nervous system leptomeningeal vascular malformations leading to seizures, cerebral atrophy, and mental retardation. Klippel-Trenaunay syndrome is characterized asymmetric overgrowth of a limb and soft tissues associated with vascular malformations, nevus flammeus, and varicosities. Internal hemangiomas and vascular malformations have also been described in this syndrome.
Other systemic anomalies described with PPV include iris hamartomas, scleral pigmentary changes, primary lymphedema, renal angiomas, moyamoya disease, scoliosis, malignant colonic polyposis, hypoplastic larynx, multiple granular cell tumors, and selective IgA deficiency.1-4
Pathogenesis and management
Although the cause of PPV is unknown, it has been proposed that the combination of vascular and pigmentary anomalies arise as a result of a genetic concept called the twin-spotting phenomenon.5,6 In this phenomenon, there is double heterozygosity with the recessive vascular mutation on 1 chromosome and the pigmentary mutation on the homologous chromosome. During embryogenesis, somatic recombination or crossing-over occurs between the homologous chromosomes, resulting in 2 different cell populations, each being homozygous for either allele.
There is no specific treatment for this disorder. Recognition of possible underlying systemic and local anomalies and complications dictates management.
Accepted for publication June 28, 1999
Drs Narchi and Santos, employed by Saudi Aramco during the time this infant was studied and when the article was written, acknowledge the use of Saudi Aramco Medical Services Organization facilities.
Reprints: Hassib Narchi, MD, Paediatric Department, Sandwell General Hospital, Lyndon, West Bromwich, West Midlands B 71 4HJ, United Kingdom.
Picture of the Month. Arch Pediatr Adolesc Med. 2001;155(2):192. doi:10.1001/archpedi.155.2.191
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