Somatic Mosaicism in Blaschkolinear Inflammatory Disorders.

Area of Science:

• Dermatology
• Genetics
• Pathology

Background:

• Linear lichen planus (LP) and linear discoid lupus erythematosus (DLE) are rare dermatologic conditions characterized by Blaschkolinear distribution of lesions.
• Blaschkolinear disorders are increasingly linked to somatic mosaicism, suggesting a genetic basis for these conditions.
• The late onset of linear LP and DLE implies a potential secondary trigger activating inflammatory responses in genetically predisposed keratinocytes.

Purpose of the Study:

• To investigate the potential role of somatic mosaicism in linear inflammatory dermatoses.
• To present histologically confirmed cases of linear LP and DLE.
• To explore therapeutic responses and identify potential targets for future treatments.

Main Methods:

• Histological confirmation of two cases of linear LP and one case of linear DLE.
• Clinical observation of lesion behavior, including recurrence and regression patterns.
• Assessment of patient response to various therapeutic interventions.

Main Results:

• Both linear LP patients exhibited episodic lesion regression and recurrence in the same distribution.
• Topical steroids and non-steroidal anti-inflammatories provided moderate symptomatic relief for LP.
• The linear DLE patient showed a gradual response to hydroxychloroquine over 14 months.

Conclusions:

• Linear inflammatory dermatoses like LP and DLE may represent localized variants of systemic disorders.
• The Blaschkolinear presentation strongly suggests an underlying cause of somatic mosaicism.
• Genetic investigation of these conditions is warranted to identify potential therapeutic targets.