Learning Objective

Describe the clinical features, causes, and pathologic changes associated with ichthyosis vulgaris and xerosis, and distinguish between inherited and acquired forms of dry skin.

Ichthyosis Vulgaris

Inheritance: Autosomal dominant

Onset: Childhood

Pathology:

• Thickened stratum corneum
• Absent stratum granulosum

Clinical Features:

• Dry, hyperkeratotic skin
• Most prominent on the trunk and extensor surfaces of limbs

Cause: Defect in epidermal barrier and keratinization

Xerosis

Very common in the elderly

Due to decreased skin lipids → impaired barrier function

Seen in:

• Aging skin
• Cancer patients receiving EGFR inhibitors (e.g., erlotinib)

Clinical Features:

• Dry, rough, itchy skin

Treatment:

• Emollients (moisturizers)
• Barrier repair creams