Which skin condition is characterized by an uneven skin tone?

Dyschromia is the correct answer because it specifically refers to the abnormal skin coloration, which can manifest as an uneven skin tone. This condition includes issues such as hyperpigmentation, hypopigmentation, or variations in skin tone that can arise from various causes like sun exposure, hormonal changes, or post-inflammatory changes following acne or injury.

The other options do not primarily focus on uneven skin tone. Rosacea is a chronic inflammatory condition primarily characterized by redness, flushing, and sometimes visible blood vessels, but not necessarily uneven skin tone. Psoriasis is an autoimmune condition that leads to rapid skin cell turnover, resulting in thick, scaly patches of skin rather than uneven pigmentation. Eczema, also known as atopic dermatitis, presents with a range of symptoms including dryness, redness, and itching, but the primary characteristics do not center on uneven skin tone.

In summary, dyschromia uniquely identifies issues with skin color or pigmentation irregularities, making it the most appropriate choice for the description of uneven skin tone.