What is the most likely description for Josh's tinea versicolor?

Tinea versicolor, also known as pityriasis versicolor, is characterized by the presence of discolored patches of skin that can either be lighter or darker than the surrounding skin. The most common manifestation is round or oval hypopigmented or hyperpigmented macules and patches, particularly found on the trunk, shoulders, and back, where the fungus disrupts the normal pigmentation of the skin.

The description of round hypopigmented macules on Josh's back aligns perfectly with these characteristics, making it the most likely observation for this condition. The fungal infection is caused by an overgrowth of Malassezia, a type of yeast that normally lives on the skin, leading to alterations in skin color due to its effects on the skin’s pigmentation process. This results in the defined, discolored spots that are typical of tinea versicolor.

To contrast, the other options describe skin conditions that do not match the typical presentation of tinea versicolor. Options that mention red papules or crusted plaques suggest other dermatological conditions such as folliculitis or dermatitis, and white streaks on the neck do not correspond to the macule appearance of tinea versicolor, further reinforcing the accuracy of the first description.