Adult-onset atopic dermatitis in a patch test population.

Area of Science:

• Dermatology
• Allergology
• Epidemiology

Background:

• Epidemiological studies on atopic dermatitis (AD) predominantly focus on childhood onset, with limited data on adult-onset AD.
• Adult-onset AD is observed in clinical practice, necessitating further investigation into its prevalence and characteristics.

Purpose of the Study:

• To determine the prevalence of adult-onset AD within a patch-test population.
• To compare the clinical features and diagnostic outcomes between early-onset AD (EOG) and adult-onset AD (AOG) groups.

Main Methods:

• A retrospective analysis of 502 adults with eczematous dermatitis undergoing patch testing, prick testing, and serum IgE measurement.
• Patients were categorized into EOG (onset ≤17 years) and AOG (onset ≥18 years) based on age of disease onset.
• Diagnostic criteria included standard and specialized patch tests, atopy patch tests (APT), and clinical evaluation.

Main Results:

• Adult-onset AD accounted for 8.8% of all eczemas, with 5.6% being 'sole' AD and 3.2% associated with contact sensitization.
• Mean SCORAD index decreased with increasing age of onset.
• No significant differences were found between EOG and AOG regarding sensitization prevalence, 'pure' vs. 'mixed' AD, or APT outcomes. Hands were the most frequently affected site in AOG.

Conclusions:

• A notable proportion of patch-test-negative eczematous cases may represent adult-onset AD.
• Further allergological testing (prick tests, IgE levels) and clinical assessment are recommended for suspected adult-onset AD.
• Larger studies are needed to validate these findings and refine diagnostic approaches for adult-onset AD.