What is xerosis cutis, particularly in older adults over 60 years old with conditions like eczema, psoriasis, or thyroid disorders?

What is Xerosis Cutis?

Xerosis cutis (also called xeroderma, dry skin, or asteatosis) is a common skin condition characterized by rough, coarse, dry skin resulting from reduced water content in the stratum corneum (below the normal 10-15% needed for supple, intact skin) and disrupted skin barrier function with abnormal keratinization and lipid metabolism. 1, 2

Clinical Characteristics and Pathophysiology

Xerosis cutis presents with the following features:

• Rough or coarse skin texture with visible scaling and desquamation 1, 3
• Modified stratum corneum structure with abnormalities in keratinization, proliferation, surface lipids, water metabolism, pH, and sebum production 3, 2
• Reduced skin water content below the 10-15% threshold required for normal barrier function 2
• Disrupted intercellular lipid structures that normally regulate skin humidity through hydrophobic constituents 2

The condition is particularly common in older adults over 60, affecting more than 50% of this population, with the highest prevalence in nursing homes and developed countries 4. Xerosis is NOT a normal part of aging, despite its high prevalence in elderly patients 5.

Risk Factors and Associated Conditions

In Older Adults with Comorbidities

Xerosis in elderly patients is multifactorial and commonly associated with:

• Intrinsic aging changes including altered keratinization and reduced lipid content 5
• Eczema and atopic dermatitis, where xerosis is a cardinal symptom requiring daily emollient use regardless of disease severity 6, 1
• Psoriasis, where dry, scaly skin is a prominent feature requiring lipid-replenishing treatments 6, 1
• Thyroid disorders (both hypo- and hyperthyroidism) as endocrine causes of xerosis 1, 3
• Medications including diuretics that contribute to skin dryness 5, 3
• Environmental factors such as overuse of heaters or air conditioners that reduce ambient humidity 5

Clinical Consequences

Xerosis causes pruritus (itching), which leads to excoriations and significantly increases the risk of secondary skin infections 5. Inflammatory skin conditions such as eczema and fissures commonly develop on xerotic skin 6. The condition severely affects quality of life and healthy aging, creating increased nursing burden 4.

Distribution Patterns

• Lower limbs show the highest prevalence of xerosis 4
• Mild xerosis is the most common severity grade encountered 4
• Prevalence is similar between males and females 4

Diagnostic Approach

Xerosis cutis is generally diagnosed on clinical grounds based on visual inspection and palpation of the skin 1. The diagnostic process should include:

• Identification of trigger factors that must be avoided 1
• Assessment of comorbidities including dermatological (eczema, psoriasis), internal (renal, hepatic, thyroid), and neurological diseases that should be adequately treated 1, 3
• Medication review for drugs that may contribute to xerosis 5, 3
• Evaluation of environmental factors and lifestyle habits 2

Common Pitfalls

A critical mistake is assuming xerosis is simply "normal aging" and not addressing it—this leads to preventable complications including pruritus, excoriations, infections, and significantly reduced quality of life 5, 4. Another pitfall is failing to identify and treat underlying conditions like thyroid disorders, eczema, or psoriasis that may be driving the xerosis 1, 3.