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Published on: September 7, 2013
Body-site distribution of melanocytic nevi in young Australian children
S L Harrison1, P G Buettner, R MacLennan
1School of Public Health and Tropical Medicine, James Cook University, Townsville, Queensland, Australia. simone.harrison@jcu.edu.au
Insights
Children in sunny Australia have more melanocytic nevi (MN), or moles, on sun-exposed skin. Higher mole counts and distribution patterns suggest sun exposure in childhood is a key factor, warranting further research into prevention.
Area of Science:
- Dermatology
- Pediatric Health
- Environmental Health
Background:
- Melanocytic nevi (MN) are common skin growths.
- Sun exposure in childhood is a known risk factor for melanoma.
- Understanding MN distribution can inform melanoma prevention strategies.
Purpose of the Study:
- To examine the body-site distribution of melanocytic nevi (MN) in children.
- To correlate MN distribution with habitually and intermittently sun-exposed body surfaces.
Main Methods:
- A cross-sectional survey was conducted in Townsville, Queensland, Australia.
- 506 white children aged 1-6 years were randomly sampled.
- Site-specific counts and densities (number per square meter) of MN were recorded.
Main Results:
- MN densities were highest on the outer forearms, upper arms, neck, and face, with feet showing the lowest density.
- Larger MN (≥2 mm) were most dense on the upper arms and trunk.
- Habitually sun-exposed sites had higher densities of small MN, while larger MN were prevalent on intermittently exposed trunk skin.
Conclusions:
- Children in this study exhibited higher MN counts and densities compared to other populations.
- The distribution of MN strongly implicates sunlight exposure during childhood.
- Further intervention studies are needed to explore the prevention of MN, a risk factor for melanoma.
Objective:
To investigate the body-site distribution of melanocytic nevi (MN) with respect to habitually and intermittently sun-exposed surfaces.
Design:
Cross-sectional survey of MN prevalence.
Setting:
Townsville (19.16 degrees S), Queensland, Australia.
Participants:
Random sample of 506 1- to 6-year-old white children who were born and raised in Townsville (response, 87.6%).
Main Outcome Measures:
Site-specific counts and densities (number per square meter) of MN.
Results:
Densities of MN of all sizes were highest on the outer forearms, followed by the outer upper arms, neck, and face. The feet had the lowest density of MN. Densities of MN of 2 mm or greater were highest on the upper arms and trunk. Boys had higher densities of MN of all sizes on the neck than girls (P = .002). Girls had higher densities of MN of 2 mm or greater on the lower legs (P = .006) and thighs (P = .005) than boys. Habitually sun-exposed body sites had higher densities, particularly of small MN, than relatively sun-protected sites, and larger MN were most prevalent on the intermittently exposed skin of the trunk.
Conclusions:
These children have higher total body and site-specific MN counts and densities than children from elsewhere, and their MN are distributed over the body in a way that implicates exposure to sunlight. As sun exposure in childhood and MN are risk factors for melanoma, intervention studies are required to determine if MN can be prevented.
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