Lichen striatus: a review

Lichen striatus (LS) is an acquired blaschkitis, with typical linear and unilateral distribution. It occurs mainly in children and is self-resolving, yet its etiopathogenesis remains widely unknown.

A review of the literature on LS cases was performed using the keyword "lichen striatus" to retrieve all relevant articles through PubMed and Google Scholar.

A total of 27 articles describing 440 LS patients were included in the present review. Mean age of patients was 3.8 years; male: female: ratio was 1:1.9. The present review confirms LS as a primarily pediatric condition, mainly affecting females. Dysregulation of the immune system might be involved in its pathogenesis, with cytotoxic T-cells attacking mosaic keratinocytes after loss of immune tolerance. The review confirms LS is mainly diagnosed clinically (80%) based on its clinical characteristics: erythematous (70%) or hypopigmented (24%) papules, distributed along the lines of Blashko. The benignity of this clinical entity is suggested by the rather short duration of disease (9.5 months on average) and by the uncommonness of therapy, adopted in only 20% of cases, and when needed, administered topically.

This review examines the complexities of LS but acknowledges limitations in data sources and calls for further research.