Linear rash from shoulder to wrist
This patient’s rash wasn’t pruritic, painful, or tender, but it formed a unique pattern.
Diagnosis: Lichen striatus
Based on the appearance and distribution of our patient’s lesions, we made a clinical diagnosis of lichen striatus, an uncommon condition that typically affects children younger than age 15.1
Lichen striatus usually presents as papulovesicular lesions in bands that follow Blaschko’s lines. (Blaschko’s lines are patterns of lines on the skin that represent the developmental growth pattern of the skin during epidermal cell migration; these lines usually aren’t visible but can be seen in patients with certain skin diseases.2) Lichen striatus most frequently affects the neck, trunk, and limbs; nail involvement is rare.1 Patients with lichen striatus are usually asymptomatic, but they occasionally have various degrees of pruritus.
The etiology of lichen striatus is unknown, but it has been reported to occur after flu-like illnesses, tonsillitis, the application of retinoic acid lotions, sunburn, hepatitis B virus infection, and bacille Calmette-Guerin vaccination.3 There is no documented relationship between lichen striatus and the HPV vaccine. Atopy may be a predisposing factor for lichen striatus, but does not trigger the disease.1
The diagnosis is typically made based on the appearance and distribution of the rash. Skin biopsy is rarely needed to establish the diagnosis.3
