What is the skin disorder characterized by a total or partial lack of melanin?

The skin disorder characterized by a total or partial lack of melanin is albinism. Albinism is a genetic condition that results in little to no melanin production in the skin, hair, and eyes. This lack of pigment can lead to lighter skin, hair that is white or very light-colored, and increased sensitivity to sunlight, as melanin plays a crucial role in protecting the skin from UV radiation.

Leukoderma, on the other hand, refers to the loss of skin color but is often used to describe conditions that are not necessarily genetic, and it can be caused by factors like damage or disease affecting the skin. Vitiligo is characterized by patches of skin losing their pigment but does not represent a complete absence of melanin throughout the body. Psoriasis is an autoimmune condition that results in red, scaly patches on the skin and is not directly related to melanin production or pigmentation disorders.

Understanding the key characteristics of albinism, particularly its genetic roots and the systemic lack of melanin, is essential for distinguishing it from other conditions affecting skin pigmentation.