Nipple-areola complex cutaneous sensitivity: a systematic approach to classification and breast volume

The aim of our study was to develop a systematic approach to provide a data bank on normative cutaneous pressure thresholds of the nipple-areola complex (NAC) in different breast volumes and a classification of the NAC sensitivity function.

A population of 150 Caucasian women stratified in five groups of 30 subjects according to the Lalardie-Jouglard classification of breast volume was enrolled in our study. A single evaluator (B.L.) performed breast volume assessments using the BREAST-V and sensory testing on NACs with Pressure-Specified Sensory Device; static and moving one- and two-point discriminations of nipple and areola were collected from each group. Statistical analysis using mixed effects model was performed with significant p-values <0.05.

Nipple was found to be more sensitive than areola for both static and moving one-point tests. From our analyses emerged an inverse relationship between skin pressure thresholds and breast volume, with NACs from small breasts (group A) statistically more sensitive than NACs from macromastia women (group E). Properly, the group A women were found to be 0.42, 1.89, 4.98, and 9.55 times progressively more sensitive (p < 0.001) than groups B, C, D, and E, respectively, for quickly adapting fibers of nipple, and 0.58, 1.97, 4.97, and 8.67 times more sensitive (p < 0.001) than groups B, C, D, and E, respectively, for quickly adapting fibers of areola. The sensitivity function of the nipple and areola was classified as high (first degree), medium (second degree), and low (third degree) according to mean ± standard deviation of the overall values.

Our study first provides a complete data bank of normative NAC sensitivity in a wide range of breast volumes, and gives three degrees of classification of NAC sensitivity function.