Nevi linked to neonatal jaundice phototherapy.

KYOTO, JAPAN -- Blue-light phototherapy for neonatal jaundice could promote development of dysplastic nevi, Dr. Zsanett Csoma asserted at an international investigative dermatology meeting.

Dr. Csoma's latest contribution to the controversial issue was in the form of a study of 618 healthy Hungarian patients aged 21-71 years. Patients born since 1968--when blue-light phototherapy for neonatal jaundice was introduced in Hungary--were found to have a 2.1-fold greater prevalence of dysplastic nevi than those who were born earlier, reported Dr. Csoma.

In an earlier cross-sectional study involving 747 patients aged 14-18 years, he found the prevalence of clinically dysplastic nevi to be 19% in those with no history of phototherapy for neonatal jaundice, compared with 25% in patients with such a history.

The proposed mechanism for the increase in dysplastic nevi lies in the emission spectrum of blue-light photo lamps, according to Dr. Csoma of the University of Szeged (Hungary). Although the spectrum centers on 450 nm, a small proportion of the emitted light--less than 1%--is UVA. Ultraviolet light not only induces melanocyte proliferation, it also has profound immunosuppressive and immunomodulatory effects in the skin and is sufficient to induce melanoma precursors in animals. These immunosuppressive effects could be magnified in the immature skin of neonates, he said.

When the earlier study was published (Pediatrics 2007;119:1036-7), it drew fire from Dr. Phyllis A. Dennery and Dr. Scott Lorch of the University of Pennsylvania, Philadelphia, and Children's Hospital of Philadelphia, who wrote that they found the data unconvincing (Pediatrics 2007;120:247-8).

"We need to remember the devastating consequences of our reduced vigilance for hyperbilirubinemia in the late 1980s and early 1990s. We must seriously weigh the resurgence of kernicterus against the potential for moles and nevi until more strategies are available to prevent hyperbilirubinemia," they cautioned.

Separately, French investigators reported that neonatal phototherapy was associated with a significant increase in melanocytic nevi 2-5 mm in diameter in a study involving 58 children aged 8-9 years. They suggested melanoma surveillance in exposed children (Arch. Dermatol. 2006;142:1599-604).

The French recommendation was deemed "premature" in a follow-up commentary by Dr. Thomas B. Newman of the University of California, San Francisco, and Dr. M. Jeffrey Maisels, chairman of the department of pediatrics at William Beaumont Hospital, Royal Oak, Mich.

"Counseling families of infants exposed to phototherapy that their child needs to be watched for melanoma is not a trivial matter. Much more evidence than was provided ... is needed before it can be recommended," they wrote (Arch. Dermatol. 2007;143:1216).

They also noted that a far larger study by dermatologists at the University of Tubingen (Germany) failed to show any association between exposure to blue light phototherapy and increased risk for development of melanocytic nevi. This study involved 1,812 children aged 2-7 years, including 333 with a history of phototherapy for neonatal jaundice (Arch. Dermatol. 2004;140:493-4).

However, according to Dr. Csoma, the German study was flawed in its focus upon 2- to 7-year-olds. While common melanocytic nevi first appear in early childhood, dysplastic nevi--the most important risk factor for melanoma--usually arise later, often around the time of puberty, the dermatologist said at the meeting of the European Society for Dermatological Research, the Japanese Society for Investigative Dermatology, and the Society for Investigative Dermatology.

His study was supported by the National Fund of the Hungarian Ministry of Health.

BY BRUCE JANCIN

Denver Bureau