A case of unilateral blaschkoid lichen planus pigmentosus

A unilateral linear pattern of lichen planus pigmentosus

Lichen planus pigmentosus (LPP) is a rare chronic variant of lichen planus. LPP distribution tends to be symmetrical and is frequently seen on the face, neck, and trunk. Atypical clinical patterns of LPP, including segmental, zosteriform, and linear, were reported in the literature. Herein, we report a rare presentation of LPP in a 16- year-old female with a unilateral linear pattern along the Blascko lines.

A Case of Unilateral Blaschko-Linear Lichen Planus Pigmentosus in a Seven-Year-Old Female: A Rare Presentation

Lichen planus pigmentosus (LPP) is a rare form of lichen planus that typically affects middle-aged people with darker-pigmented skin. LPP is associated with a longer clinical course than classical lichen planus, which distinguishes it clinically. Its occurrence in children is uncommon, with few reported cases in this population in the literature. We report a rare presentation of unilateral blaschkoid LPP in a seven-year-old Saudi Arabian female patient.

Unilateral Lichen Planus Pigmentosus with Blaschko's Line Distribution: A Case Report

Lichen planus pigmentosus (LPP) is a distinctive variant of lichen planus described for the first time in 1974. A wide range of presentations and distribution patterns have been reported, mainly presenting as dark brown hyperpigmented macules and patches, typically involving sun-exposed areas such as the face, neck, and flexural folds. It is more common in dark-skinned patients with a female predominance. Infrequently, LPP may present as a Blaschkoid distribution, with only a few cases reported in the medical literature. We report an unusual case of LPP that developed with a unilateral Blaschkoid distribution on the left side of the trunk in a 32-year-old female following weight reduction surgery.

Positive Antinuclear Antibody and Blaschkoid Lichen Planus Pigmentosus

Lichen planus pigmentosus is a rare variant of lichen planus. It is an acquired pigmentary disorder of unknown etiology. It is characterized by dark brown and slate gray macules and patches. The nails, scalp, and oral mucosa are usually spared, unlike lichen planus. Lichen planus pigmentosus commonly involves the head and neck region as well as intertriginous areas such as the axillae, inframammary and inguinal regions. It can be associated with autoimmune diseases, endocrinopathies, and other variants of lichen planus such as fibrosing alopecia of the scalp. Variable clinical patterns of lichen planus pigmentosus including zosteriform, linear, and segmental had been published. Histopathologically, it is characterized by hyperkeratosis of the epidermis, hypergranulosis, variable degrees of lichenoid infiltration depending on the age of the lesion, and prominent melanin incontinence. Recent updates on erythema dyschromicum perstans that were considered similar to lichen planus pigmentosus, concluded that they could be differentiated on clinical bases as well as histopathology. Epidermal hyperkeratosis, hypergranulosis, apoptotic cells, lichenoid dermatitis, periappendageal infiltrate, and fibrosis with marked superficial dermal melanin incontinence aid to differentiate lichen planus pigmentosus from erythema dyschromicum perstans. During embryogenesis, cells migrate and follow developmental lines named after Blaschko, a German dermatologist, who first noted them. Blaschko’s lines (BL), do not follow neural, vascular, or lymphatic pathways. They appear as V-shaped on the back, S-shaped on the abdomen, and linearly on limbs. We report a case of lichen planus pigmentosus over BL that is a rare presentation of the disease and associated positive antinuclear antibody (ANA) without overt manifestations of any connective tissue disease.