Lichen striatus case report
A 4-year old boy with good past health developed a rough patch over his left leg, just below the knee, which later extended down to the lower leg and foot over the past 6 months. The lesion was asymptomatic and did not improve with antifungal and topical steroid prescribed by general practitioners. Physical examination revealed a linear band of hypopigmented scaly patches over left leg, extending below knee to left foot and toe (Figure 1). The clinical diagnosis of Lichen striatus was made.
Lichen striatus often appears as a sudden eruption of small papules on an extremity. The papules are usually asymptomatic, reaching maximum involvement within several days to weeks. Lichen striatus is self-limited, but it may resolve with postinflammatory hyper or hypopigmentation.
Well established lesion appears as a continuous or interrupted, linear band consisting of small (1- to 3-mm) pink, tan, or skin-colored lichenoid papules. The papules may be smooth, scaly, or flat topped. The band may range from a few millimeters to 1-2 cm wide and extends from a few centimeters to the full length an extremity. The lesions are usually unilateral and single on an extremity along the lines of Blaschko. The lesions are most commonly located on a proximal extremity and less commonly on the trunk, head, neck, or buttock.
The etiology of Lichen striatus is unknown. skin biopsy can be performed to confirm the diagnosis of Lichen striatus, but this is rarely necessary.
Because Lichen striatus is a self-limited disorder and because the lesions spontaneously regress within 3-12 months, no treatment is needed. The patient and family should be reassured.
Prognosis of patients with Lichen striatus is excellent. Recovery is complete. Lichen striatus lesions usually regress spontaneously within 1 year, with a range of 4 weeks to 3 years. Relapses of Lichen striatus may occur, but these are uncommon.
Figure 1. A linear band of hypopigmented scaly papules and patch extended from the knee to the ankle and foot.
