Texas Medical Assistant Certification Practice Test

Which pigmentation disorder is characterized by large white patches of skin?

1. Chloasma

2. Melasma

3. Vitiligo

4. Albinism

The correct answer is: Vitiligo

The pigmentation disorder characterized by large white patches of skin is vitiligo. This condition occurs when melanocytes, the cells responsible for producing skin pigment, are destroyed or stop functioning. As a result, areas of the skin lose their color, creating distinct white patches that can appear anywhere on the body. Vitiligo can vary in severity, with some individuals experiencing only a few small patches, while others may have extensive areas affected. In contrast, chloasma and melasma refer to hyperpigmentation disorders often associated with hormonal changes, commonly seen in pregnant women or those taking oral contraceptives. They typically present as brown or tan patches on the face, rather than white patches. Albinism is a genetic condition that results in a lack of melanin production throughout the body, leading to lighter skin, hair, and eyes, but unlike vitiligo, it does not cause defined patches of depigmented skin. Therefore, vitiligo is the correct answer as it specifically presents with large white patches of skin.