Each beach vacation from birth to age 6 by white Colorado children was associated with a 5% increase in small nevi when the children were examined at age 7, but not with large nevi development.
In addition, the total estimated UV dose received on waterside vacations and the number of days spent on vacation were not significantly related to nevi count, suggesting that a threshold dose of UV exposure is received relatively early during each waterside vacation, such that 3-day-long getaways may have the same effect on nevi development as 10-day trips, according to the authors.
Although it is the larger nevi (greater than or equal to 2 mm) that are most commonly associated with skin cancer, increased numbers of small nevi in childhood also confer melanoma risk.
“Parents should be aware of the effect that vacations may have on their children's risk for developing melanoma as adults, and they should be cautious about selection of vacation locations,” wrote Dr. Kelly J. Pettijohn, from the department of community and behavioral health at the Colorado School of Public Health, Denver, and associates.
A total of 681 children born in 1998 who were lifetime residents of Colorado were studied. Patients' parents were asked in 20- to 30-minute phone interviews about the child's vacation history, sunburn history, and demographic data. Skin exams were also conducted in 2005, when the patients were 7 years old (Cancer Epidemiol. Biomarkers Prev. 2009;18:454–63).
A history of severe sunburn, of sunscreen use, of hat use, or of sun sensitivity failed to predict the development of nevi. “The only significant linear relationship between vacations and nevi less than 2 mm was for number of waterside vacations before age 6,” wrote the authors.
Each vacation was associated with a 5% increase in these small nevi after controlling for other factors.
In addition, the authors found that waterside vacations taken within 1 year of the skin exam did not affect small nevi counts. This finding suggests a time lag of at least 1 year may be necessary for the effects of sun exposure during waterside vacations to result in new nevi, they noted. The authors reported no potential conflicts of interest.
Parents should be made aware of the effect that vacations have on their children's risk of melanoma. Louise A. Koenig/Elsevier Global Medical News