What is the primary cause of hyperpigmentation?

Hyperpigmentation primarily occurs due to the over-activity of melanocytes, which are the cells responsible for producing melanin, the pigment that gives skin its color. When these cells become overactive, they produce excess melanin, leading to darkened patches or spots on the skin. This condition can result from various stimuli, including sun exposure, hormonal changes, or inflammation, which can trigger melanocyte activity.

While genetic predisposition can influence skin pigmentation patterns, the direct cause of increased pigmentation seen in hyperpigmentation is the heightened activity of melanocytes. Other options, like inadequate sun exposure and milk allergies, do not directly relate to the mechanisms involved in hyperpigmentation, making them less relevant in this context.