What skin disorder is characterized by abnormal light patches due to pigment cell destruction?

Leukoderma is a skin disorder marked by the presence of lighter patches on the skin, which occur as a result of the destruction or dysfunction of melanocytes, the cells responsible for producing the pigment melanin. This loss of pigment can be caused by various factors, such as autoimmune conditions, genetics, or exposure to certain chemicals. The condition leads to the formation of hypo-pigmented areas on the skin, which is why it is identified specifically as a disorder characterized by abnormal light patches.

When distinguishing between other options, miliaria rubra refers to heat rash caused by blocked sweat glands and does not involve changes in pigmentation. Malignant melanoma is a serious type of skin cancer that typically presents as dark spots or moles rather than lighter patches. Nevus, commonly known as a mole, refers to a localized growth of melanocytes and also does not manifest as lighter patches of skin. Thus, leukoderma stands out as the correct answer due to its specific characteristic of lightened areas resulting from pigment cell destruction.