PSI Barbering Practice Exam 2026 - Free Barbering Practice Questions and Study Guide

The thickening of a callus that grows inward is referred to as a corn. Corns are a specific type of callus that typically form on the toes and are characterized by their conical shape, which develops as a response to pressure or friction. Unlike regular calluses, which may spread out on the surface of the skin, corns penetrate deeper into the skin tissue, creating discomfort or pain when pressure is applied.

The other options do not describe the inward growth phenomenon. Warts are caused by a viral infection and can appear anywhere on the body, often with a rough surface rather than a thickening that grows inward. Neoplasms refer to any new, abnormal growth of tissue, which could be benign or malignant and does not specifically pertain to thickened skin. Lastly, a mole is a growth on the skin that typically consists of pigmented cells and has a different origin and appearance than a corn. Thus, identifying a corn is essential for understanding the specific skin condition related to pressure and friction.