PPV case offers treatment challenges

Newport Beach, Calif. - Most dermatologists are unlikely to see patients with phacomatosis pigmentovascularis (PPV). Those who do, however, should know how to recognize and treat the condition with an eye toward preventing concomitant systemic symptoms.

A recently presented case helps illustrate PPV's diagnostic subtleties and treatment challenges. A now 2-year-old Hispanic boy presented at Western University of Health Sciences' dermatology service in Mesa, Ariz., with red spots in his cheeks that extended to his sternum bilaterally and flared with crying or increased temperatures. Within these spots, the boy's mother also noticed unusually shaped areas of pigmentary loss, although the patient possessed no history of developmental abnormalities.

"In the past, he'd also been diagnosed with Mongolian spots that covered roughly 40 percent of his body's surface area," says Sam P. Smith, D.O., a third-year dermatology resident at Western University. "He also had an epidermal nevus on his neck, a nevus spilus on his back and a port wine stain on his face. Based on these physical findings, we came up with a diagnosis of PPV."

"Based on different physical findings, PPV is grouped into five different types, four in the literature and a fifth type that's been recently proposed (Landro A, Tadini G. Ped Dermatology 1999.16:25-30). They differ based on which type of melanocytic lesions are present. They're also grouped into subtypes - subtype A being purely skin lesions, B also involving systemic lesions," Dr. Smith says.

Dermatologic literature contains only about 125 reported cases since the condition was first described in 1947.

"However, that number may be a little misleading, because, most of the time, it's just the disease with systemic findings that's reported rather than the cases that include only cutaneous manifestations," he says.

PPV is believed to be an embryologic abnormality that usually occurs after the first two months of development in response to an insult such as a drug or virus.

Dr. Smith says, "It's believed to be a disruption of melanocyte migration and decreased vascular development. So it's referred to genetically as a twin loci theory. On each chromosome pair there are two distinct recessive mutations. The first mutation leads to the pigmentary changes; the second causes the vascular changes. Generally, you have more of a heterozygous cell population, and you don't see any clinical abnormalities. But with PPV, there's a crossover known as somatic recombination, (which leads to) these site-specific homozygous cell populations. These homozygous cell lines present as clinical abnormalities."

What was perhaps unique about Dr. Smith's patient was that he demonstrated characteristics of two types of PPV.

"We classified him as PPV Type 4 because he had Mongolian spots and the nevus spilus. In addition, he also had an epidermal nevus, which is usually only found in Type 1," Dr. Smith says.

Ultimately, he referred the patient to Ronald Hansen, M.D., at Phoenix Children's Hospital. He discussed treatment options with the boy's mother.

Because the skin lesions are purely cosmetic at this point, "no treatment necessarily has to be done on those," Dr. Smith says. "Some patients have systemic problems associated with PPV, which can include Klippel-Trenaunay and Sturge-Weber syndromes, but this patient doesn't seem to have these problems."

Treating PPV requires physicians to address the melanocytic or pigmented lesion first. This is done with a Q-switched alexandrite (755 nm) or ruby (694 nm) laser with an optimal pulse duration of 70 to 250 ns. Next, treating the vascular lesion requires a flashlamp pulsed dye laser.