Which of the following conditions is characterized by excessive scaling of the skin?

Psoriasis is characterized by excessive scaling of the skin due to an overproduction of skin cells. This condition typically presents as thick, red patches covered with silvery-white scales, particularly on areas such as the elbows, knees, and scalp. The accelerated growth cycle of skin cells leads to the buildup of these scales, making psoriasis distinct from other skin conditions.

While dermatitis and eczema can also involve scaling, they usually present with additional symptoms such as inflammation and itching. Dermatitis encompasses various types, including contact dermatitis, which may not necessarily involve extensive scaling. Similarly, eczema, which is often used interchangeably with atopic dermatitis, primarily features dry, itchy skin that may become red and inflamed but does not typically exhibit the thick scaling characteristic of psoriasis. Acne, on the other hand, is a condition primarily associated with clogged pores and inflammation rather than excessive skin scaling.

Thus, psoriasis stands out among these options due to its unique hallmark of excessive scaling, making it the correct answer.