Study of Risk Factors for the Presence of Interdigital Nevi of the Feet. / Estudio de los factores de riesgo de la presencia de los nevus interdigitales de los pies.

ABSTRACT

BACKGROUND AND OBJECTIVES: No studies focused on counting the interdigital acquired melanocytic nevi (AMN) of the foot (IDNf) have ever been conducted. Therefore, our objective was to study the relationship between the presence of IDNf and the total number of AMN in the feet and the rest of the body, the racial phenotypic characteristics, and other risk factors for melanoma. MATERIAL AND METHODS: We conducted a cross-sectional observational study with 255 patients ≥18 years old who attended our Dermatology Unit from September 2020 through February 2021, and included all AMN ≥1mm from the feet and ≥2mm from the rest of the bod. The association between the variables was studied using univariate and multivariate logistic regression models. RESULTS: The presence of IDNf was significantly and independently associated with the presence of plantar AMN and body counts ≥50 AMN. However, no significant differences were observed regarding sex, age, personal history of melanoma, presence of nevi on the dorsum of the foot, history of sunburn or UV rays, or racial phenotypic characteristics. CONCLUSIONS: The presence of IDNf is associated with a higher count of plantar nevi and total AMN in the body, meaning that interdigital spaces of the foot-anatomical expansions of the sole and other possibly genetic causes-could be responsible for the number of AMN found in this location, as these regions are not photoexposed.