There are several different types of ichthyosis. Some mainly affect the skin, such as:
- ichthyosis vulgaris
- X-linked ichthyosis
- congenital ichthyosiform erythroderma (also known as non-bullous ichthyosiform erythroderma)
- lamellar ichthyosis
- epidermolytic hyperkeratosis (also known as bullous ichthyosiform erythroderma)
- harlequin ichthyosis.
Others are multi-system disorders, affecting other body systems, such as the nervous or immune systems, such as:
- Netherton syndrome
- Sjögren Larsson syndrome
- Refsum disease
- neutral lipid storage disease
- KID syndrome (a rare congenital disorder characterised by keratitis, ichthyosis, and deafness)
- Conradi-Hunermann syndrome.
Scaling varies in severity, from relatively mild scaling in ichthyosis vulgaris to the severe constricting plate-like scale of harlequin ichthyosis. Depending on the condition there may also be redness or blistering.