What defines ichthyosis?

Ichthyosis is characterized by scaly skin that resembles that of a fish, which is what makes the second choice the correct definition. This condition involves a genetic disorder that leads to a buildup of keratin in the outer layer of the skin, resulting in dry, flaky patches that can vary in severity. It is important to recognize that ichthyosis manifests primarily with these distinct scales and dryness, distinguishing it from other skin conditions.

The other options describe different skin issues that do not align with the nature of ichthyosis. Excessive oiliness of the skin pertains to seborrhea or oily skin conditions, which is fundamentally different from the dry, scaly texture associated with ichthyosis. Red patches on the face typically suggest conditions like rosacea or eczema, both of which are inflammatory rather than thickening or scaling disorders. Increased perspiration can relate to hyperhidrosis, which also does not correlate with the symptoms of ichthyosis. Understanding these key differences reinforces the distinctive characteristics of ichthyosis.