What is the likely etiology of darkened skin and light-colored lesions on the trunk after sun exposure?

What is the likely etiology of darkened skin and light-colored lesions on the trunk after sun exposure?

• A. Tinea Versicolor
• B. Psoriasis
• C. Actinic Keratosis
• D. Melasma

Answer: (A)

The combination of darkened skin and light-colored lesions on the trunk after sun exposure suggests a condition that is typically associated with a change in skin pigmentation due to factors such as sun exposure. Tinea Versicolor, a fungal skin infection caused by the overgrowth of Malassezia yeast, often leads to light or hypopigmented patches on a darker skin background. This is particularly noticeable after sun exposure because the affected areas do not tan like the surrounding skin, resulting in a contrast that can look like light-colored lesions against a darker backdrop. In contrast, psoriasis typically presents with raised, red plaques covered with silvery scales, which usually do not manifest as light-colored lesions following sun exposure. Actinic keratosis is associated with rough, scaly patches that occur due to sun damage but do not typically appear as light-colored lesions against darkened skin. Melasma is characterized by brown or tan patches, particularly on sun-exposed areas, but does not lead to light-colored lesions. This distinctive presentation of Tinea Versicolor aligns perfectly with the observed changes after sun exposure, which makes it the most plausible etiology in this scenario.

The combination of darkened skin and light-colored lesions on the trunk after sun exposure suggests a condition that is typically associated with a change in skin pigmentation due to factors such as sun exposure. Tinea Versicolor, a fungal skin infection caused by the overgrowth of Malassezia yeast, often leads to light or hypopigmented patches on a darker skin background. This is particularly noticeable after sun exposure because the affected areas do not tan like the surrounding skin, resulting in a contrast that can look like light-colored lesions against a darker backdrop.

In contrast, psoriasis typically presents with raised, red plaques covered with silvery scales, which usually do not manifest as light-colored lesions following sun exposure. Actinic keratosis is associated with rough, scaly patches that occur due to sun damage but do not typically appear as light-colored lesions against darkened skin. Melasma is characterized by brown or tan patches, particularly on sun-exposed areas, but does not lead to light-colored lesions.

This distinctive presentation of Tinea Versicolor aligns perfectly with the observed changes after sun exposure, which makes it the most plausible etiology in this scenario.