Bilateral zosteriform extragenital lichen sclerosus

Area of Science:

• Dermatology
• Pathology

Background:

• Extragenital lichen sclerosus (ELS) is a chronic inflammatory skin condition.
• ELS typically affects the genital area but can occur elsewhere.
• Zosteriform ELS, following Blaschko lines, is a rare presentation.

Observation:

• A 35-year-old man presented with asymptomatic, bilateral, linear eruptions on forearms and legs.
• Clinical examination revealed pearly white papules and depigmented atrophic plaques with telangiectasia.
• Lesions followed Blaschko lines, with sparing of genitalia, oral mucosa, palms, and soles.

Findings:

• Differential diagnoses included lichen striatus and ELS.
• Clinical features favored ELS.
• Histopathology confirmed lichen sclerosus with hyperkeratosis, epidermal atrophy, vacuolar degeneration, and dermal changes.

Implications:

• This case expands the understanding of ELS clinical presentations.
• Recognizing zosteriform ELS is crucial for accurate diagnosis and management.
• The findings emphasize the importance of histopathological correlation in diagnosing rare dermatoses.