Which condition is characterized by dry skin that resembles fish skin?

The condition characterized by dry skin that resembles fish skin is ichthyosis. Ichthyosis is a genetic skin disorder that leads to an abnormality in the skin's ability to shed dead cells, resulting in thick, dry, and scaly skin that often has a texture similar to that of fish scales. This condition can vary in severity and can affect large areas of the body.

The other conditions listed, while they might involve skin dryness or scaling, do not typically produce the distinct fish scale appearance associated with ichthyosis. Psoriasis is characterized by red patches with silvery scales, and eczema presents as inflamed, itchy skin that may become crusty or weepy. Dermatitis refers to inflammation of the skin from various causes, which can include rashes and irritation but is not specifically associated with the fish-like scaling seen in ichthyosis. Thus, ichthyosis is the term that accurately reflects the specific characteristics described in the question.