Nail Dystrophy in Patients with Atopic Dermatitis and Its Association with Disease Severity

BACKGROUND: Nail dystrophy arises from various inflammatory dermatologic diseases. However, there have been few reports on the prevalence of nail abnormality in atopic dermatitis (AD) or on the relationship of this condition with the severity of the disease. OBJECTIVE: This study was intended to determine the prevalence and types of nail abnormalities associated with AD and to evaluate the relation between nail abnormalities and the severity of AD. METHODS: AD patients aged 2 to 19 who visited the outpatient clinic were thoroughly examined for nail abnormalities. Demographic information was collected and eczema area and severity index (EASI) score for severity of AD were checked. RESULTS: A total of 235 AD patients (children and adolescents) were investigated. There were 24 (10.2%) patients with nail abnormalities: transverse groove (Beau's line) (25.0%), nail pitting (16.7%), koilonychia (16.7%), trachyonychia (12.5%), leukonychia (12.5%), brachyonychia (8.3%), melanonychia (8.3%), onychomadesis (8.3%), onychoschizia (8.3%), and onycholysis (8.3%). There was no statistically significant difference in the total EASI score associated with development of nail abnormalities (p=0.236). However, when the EASI score was confined to the lower extremities, it showed a relation to the prevalence of toe nail dystrophy (odds ratio, 1.115; 95% confidence interval, 1.014~1.316; p=0.030). CONCLUSION: Nail abnormalities in AD are thought to be caused mainly by pathologic change in the nail matrix region, and the EASI score confined to lower limbs, might be used as a predictor of toe nail changes in patients with AD.