ICHTHYOSIS: clinical and molecular update. Part 2: syndromic ichthyosis. Diagnostic and therapeutic approach of ichthyosis.

Syndromic ichthyoses are a group of disorders whose genetic alterations impact both epidermal and non-epidermal tissues. Therefore, patients present symptoms in other organs. Most are extraordinary and, in some, ichthyosiform desquamation has been poorly described.

ICHTHYOSIS: clinical and molecular update. Part 1: introduction and non-syndromic ichthyoses.

Ichthyoses are a heterogeneous group of diseases sharing symptoms and a common etiopathogenic mechanism. Clinically, these diseases are characterized by the presence of erythema and variable degrees of skin thickening and desquamation. Although the affected area, severity, and molecular substrate are very variable, they are all signs of a disruption of the barrier formed during epidermal differentiation.

Ichthyosis.

The ichthyoses are a large, heterogeneous group of skin cornification disorders. They can be inherited or acquired, and result in defective keratinocyte differentiation and abnormal epidermal barrier formation. The resultant skin barrier dysfunction leads to increased transepidermal water loss and inflammation.

Polymorphisms in genes implicated in base excision repair (BER) pathway are associated with susceptibility to Paget's disease of bone.

Paget's disease of bone (PDB) is a chronic bone metabolic disorder. Currently, PDB is the second most frequent bone disorder. PDB is a focal disorder affecting the skeleton segmentally but the cause of which is unknown.