Background Lichen striatus is an common dermatosis that follows the lines of Blaschko. Aetiology of this eruption is unknown, its features are less known to paediatricians.

Objective We attempted to characterise the clinical, pathologic features and evolution of one case presented to the paediatric departament in our clinic.

Materials and methods A 2-year-old girl, atopic, presented with fever and upper respiratory tract infection.

Clinical examination: one month long dull-red papulo-squamous dermatosis arranged in a Blaschko line. The eruption appeared suddenly a month ago. The skin lesions were asymmetrically distributed linearly unilateral along the left arm, arranged in a Blaschko line pattern. Intense itching was present in this case.

Laboratory results: Hb = 12,6 g/dl, Ht = 35,2%, WBC = 9400/µL, S = 25%, Eo = 2,5%, Ba = 0,745%, Ly = 71,1%, RBC = 4,38 × 10 mil/µL, PLT = 336000 µL, ALT = 23 U/L, AST = 31 U/L, CRP = 0,6 mg/dL; Creatinin, Immunogram, Glucose –normal; HIV 1 + 2, Ag HBs, Anti HCV-negative

Histopathology revealed features consistent with lichen striatus.

Tratament for itchy lichen striatus consisted in topical steroid application (mometasone furoate 1% cream once daily for two weeks).

Five months later, complete resolution of the skin lesions occurred without any other treatment, leaving only slightly hypopigmented macules on the left arm.

Conclusion

1. That lesions of lichen striatus may have a prolonged active phase, the differential diagnosis includes other inflammatory diseases that can assume a linear pattern, paediatrician and dermatologist must team up in these cases;

2. Post-inflammatory hypopigmentation can be a cause for concern for the parents and their children.