**Question:** In a patch of vitiligo

A. Loss of melanocytes
B. Decreased pigmentation
C. Inflammation
D. Enhanced immune response

**Core Concept:** Vitiligo is a pigmentary disorder characterized by the loss of melanocytes, which are pigment-producing cells responsible for skin color. The primary cause of vitiligo is not fully understood, but it is believed to result from a combination of genetic and immunological factors.

**Why the Correct Answer is Right:** The correct answer, A) Loss of melanocytes, accurately describes the main feature of vitiligo. Melanocytes are destroyed in affected areas, leading to reduced melanin production and subsequent depigmentation.

**Why Each Wrong Option is Incorrect:**

B) Decreased pigmentation is partially correct but does not address the underlying cause of the condition. Melanin levels may be reduced, but the focus of vitiligo lies in the loss of melanocytes.

C) Inflammation is not the primary cause of vitiligo. While inflammation may be present in some cases, the main driver of the disease is the destruction of melanocytes.

D) Enhanced immune response is a contributing factor in vitiligo development. However, it is not the sole cause, as the loss of melanocytes is the primary feature of the disease.

**Clinical Pearl / High-Yield Fact:** Vitiligo is often associated with autoimmune disorders like thyroid disorders and autoimmune diseases. Additionally, the coexistence of vitiligo and hypopigmented areas on the skin of patients with autoimmune diseases suggests a possible autoimmune basis for vitiligo. Understanding the immunopathogenesis is vital for diagnosing the condition and selecting appropriate treatment options.

**Correct Answer:** A) Loss of melanocytes