Ichthyosis vulgaris

Ichthyosis vulgaris is a common skin condition that affects the outer layer of the skin, causing it to become dry, thickened, and scaly. It primarily involves the skin's ability to shed dead cells properly, leading to a buildup of rough, plate-like scales. This condition usually appears in early childhood and mainly affects the arms, legs, and trunk. The skin changes can cause itching and discomfort, and the scales often worsen in cold, dry weather. Although it is a chronic condition, it does not affect internal organs or overall health but can impact quality of life due to its visible appearance and skin symptoms.

Ichthyosis vulgaris is a genetic disorder characterized by defective skin barrier function due to mutations in the FLG gene encoding filaggrin, a key protein in epidermal differentiation. This leads to impaired keratinocyte aggregation and abnormal desquamation, resulting in hyperkeratosis and scaling of the skin. It is the most common form of ichthyosis and typically inherited in an autosomal semi-dominant pattern. Clinically, it presents with fine, polygonal scales predominantly on the extensor surfaces of the limbs and trunk, with relative sparing of flexural areas. The condition is associated with xerosis (dry skin) and often coexists with atopic dermatitis. The major clinical significance lies in its chronicity and potential for secondary skin infections due to barrier disruption.