Lichen striatus, also known as acquired blaschkoid dermatitis, is a rare condition primarily observed in children, with most cases occurring between the ages of 5 and 15. While less common in adults, its presentation typically includes discrete, skin-colored to pink or erythematous flat-topped papules, which may merge to form a red, possibly scaly, band. This eruption often follows the Blaschko lines and predominantly affects the extremities. Nail involvement, characterized by thickening, ridges, splitting, or loss, can also occur with or without skin lesions.

The condition is generally benign and tends to resolve on its own without the need for extensive investigation or treatment. Studies suggest that lichen striatus may stem from epigenetic mosaicism or environmental triggers such as vaccinations after Bacille Calmette-Guerin (BCG) and hepatitis B vaccinations, UV light exposure, or infections like varicella and influenza. Although rare, occurrences during pregnancy or postpartum may relate to an autoimmune response triggered by gestation.

Lichen striatus typically resolves within a year without scarring, though temporary hypopigmentation or hyperpigmentation may occur. Treatment may not be necessary in many cases, but for those seeking cosmetic improvement or symptomatic relief from itching, low-to-moderate potency topical corticosteroids or immunomodulators can be used. Additionally, bleaching creams may help address post-inflammatory hyperpigmentation.