Related Experiment Video
Updated: Oct 6, 2026

Effects of Exposure of Formaldehyde to a Rat Model of Atopic Dermatitis Induced by Neonatal Capsaicin Treatment
Published on: September 27, 2017
Palmar hyperlinearity is associated with persistent atopic dermatitis trajectory with high allergic risk: The
Reiji Kojima1, Masataka Kawai2, Tadao Ooka3
1Department of Epidemiology, School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, Japan.
Background:
Palmar hyperlinearity (PH) is a minor diagnostic criterion for atopic dermatitis (AD) proposed by Hanifin and Rajka and is associated with loss-of-function variants in the filaggrin (FLG) gene. Although FLG variants are linked to the long-term course of AD, evidence on the relationship between PH and AD trajectories is limited. We investigated the association between PH and long-term AD outcomes in children.
Methods:
We analyzed data from 1769 children in the Yamanashi Adjunct Study of the Japan Environment and Children's Study. PH was assessed by pediatric allergy specialists blinded to AD trajectories and by an artificial intelligence (AI)-based assessment. AD trajectories were identified using longitudinal latent class analysis based on eight assessments between 6 months and 6 years of age. Associations between PH and AD trajectories were examined using multinomial logistic regression with the never/infrequent group as reference.
Results:
PH was identified in 34 children (1.9%) and AI-based PH in 10 (0.6%). Four AD trajectories were identified: persistent (8.5%), early-onset (16.7%), late-onset (10.3%), and never/infrequent (64.6%). PH was significantly associated with persistent AD (adjusted OR 3.60, 95% CI 1.49-8.67) but not with early- or late-onset phenotypes. Similar findings were observed for AI-based PH. Persistent AD was also associated with allergic symptoms (food allergy, asthma, allergic rhinitis) at age 6 and allergic sensitization at age 8.
Conclusions:
PH was associated with an AD phenotype characterized by a more persistent disease course.
Related Concept Videos
Asthma-II: Pathophysiology and Classification
Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition.
Critical processes in asthma pathophysiology include:
Asthma: Pathogenesis and Management
Asthma is classified as allergic and non-allergic. Allergens such as dust mites, pollen, and pet dander trigger allergic asthma, while factors like cold air, intense emotions, or exercise can induce non-allergic asthma.
Asthma III: Clinical Manifestations
Allergic Reactions
Papillary Dermis
The dermis might be considered the "core" of the integumentary system, as distinct from the epidermis and hypodermis. It contains blood and lymph vessels, nerves, and other structures, such as hair follicles and sweat glands. The dermis is made of two layers of connective tissue that comprise an interconnected mesh of elastin and collagenous fibers, produced by fibroblasts.
Papillary Layer
The papillary layer is made of loose, areolar connective tissue, which means the collagen and...
Asthma-IV: Diagnostic and Management
Clinical Assessment for Asthma:
This is the first step in diagnosing and managing asthma. It includes: