Systematized linear epidermolytic hyperkeratosis.

Area of Science:

• Dermatology
• Clinical Genetics
• Pathology

Background:

• Epidermolytic hyperkeratosis (EHK) is a rare genetic disorder of keratinization.
• It typically presents at birth or early infancy with generalized skin scaling and blistering.
• Linear or systematized variants are less common but recognized presentations.

Observation:

• A 5-year-old boy exhibited asymptomatic, widespread verrucous plaques following Blaschko's lines.
• Lesions were noted on the trunk and extremities, accentuated in flexural areas.
• No history of blistering, redness, or family history of similar conditions was reported.

Findings:

• Differential diagnoses included Ichthyosis hystrix and generalized linear/mosaic EHK.
• Histopathological examination of skin biopsies revealed characteristic epidermolytic hyperkeratosis.
• The findings confirmed the diagnosis of systematized linear EHK.

Implications:

• This case highlights a rare presentation of EHK along Blaschko's lines.
• Accurate diagnosis relies on clinical morphology and characteristic histopathological findings.
• Understanding these variants is crucial for appropriate patient management and genetic counseling.