Blaschkoid lichen planus: Throwing a “curve” in the nomenclature of linear lichen planus

Lichen planus is a distinctive mucocutaneous disease with well-established clinical and histopathologic criteria. Lichenoid eruptions closely resemble lichen planus and may sometimes be indistinguishable from it. Systemic agents previously associated have included medications, viral infections and vaccines. Sporadic case reports of lichen planus and lichenoid reactions associated with COVID-19 vaccines have recently emerged. Herein, we review the world literature (31 patients) and expand it with a case series of 15 patients who presented with vaccine-induced lichenoid eruption (V-ILE). The spectrum of clinical and histopathologic findings is discussed with emphasis on the subset whose lesions manifested in embryologic fusion lines termed lines of Blaschko. This rare Blaschkoid distribution appeared in seven of the 46 patients studied. Of interest, all seven were linked to the mRNA COVID-19 vaccines. We believe that all lichenoid eruptions should be approached with a heightened index of suspicion and patients should be specifically questioned with regards to their vaccination history. When diagnosed early in its course, V-ILE is easily treated and resolves quickly in almost all patients with or without hyperpigmentation. Additional investigative studies regarding its immunopathology and inflammatory signaling pathways may offer insight into other Th1-driven autoimmune phenomena related to COVID-19 vaccination.

Lichen linear planus is a rare variant of lichen planus that appears as pruritic, polygonal, purple papules in a blaschkoid distribution. This review critically assesses all reported cases of linear lichen planus (LLP) for proposed etiology, clinical and histologic traits, treatment options, and recurrence. A PubMed search from inception through March 2023, followed by article screening and full-text review, identified 51 unique cases of LLP. Data from each case including the sex of the patient, anatomic distribution of lesions, biopsy results, proposed etiology, treatment, and recurrence were recorded. LLP did not show a significant gender or age predilection, most frequently presented unilaterally with pruritus, and involved numerous anatomic regions. Various triggers including metal implants, vaccinations, infections, malignancy, and pregnancy were identified. The most common histopathologic descriptions included band-like lymphocytic or lichenoid infiltrate, basal liquefactive, vacuolar degeneration, hypergranulosis, hyperkeratosis, civatte or colloid bodies, melanin incontinence, and orthokeratosis. Treatment options, duration of treatment, and recurrence rate of LLP lesions were variable. Although LLP is rare, dermatologists should be aware of this presentation and appropriate diagnostic and treatment options because swift diagnosis can reduce patient morbidity.

BACKGROUNDLichen planus (LP) with distribution of lesions along Blaschko’s lines is a rare entity, accounting for 0.24%-0.62% of all patients. Unilateral distribution of lesions in arm, leg, trunk, and waist is even less common. Approximately 10% of patients with LP manifest nail lesions.CASE SUMMARYA 20-year-old woman presented to our department with polygonal, purpuric, flat-topped papules over the right arm, right leg, and right side of trunk and waist for the last 5 mo. The patient initially developed nail deformation in the left middle finger with no obvious cause, followed by development of blue-purple and red maculopapular rash with pruritus. During the disease course, the skin lesions aggravated and spread to several segments due to scratching. The lesions showed unilateral distribution along the Blaschko’s lines. The diagnosis of LP along Blaschko’s lines was established based on dermoscopy and skin biopsy. Her cutaneous lesions considerably improved after 4-wk treatment with intramuscular glucocorticoid, oral acitretin, topical glucocorticoid, and retinoids.CONCLUSIONCases of LP involving multiple segments of the body along the Blaschko’s lines with nail damage are rare.

Lichen planus (LP) is a relatively uncommon chronic skin condition with varied clinical presentations seen mostly in adults. It is rarely encountered in children, although increasingly more pediatric cases are being recognized and reported. LP can affect skin, mucosae, hair and nails, alone or in various combinations. All forms of LP seen in adults also occur in children. Certain types (eruptive, generalized) are observed more commonly in children than adults whereas appendageal (follicular and nail), mucosal (oral, genital, esophageal), hypertrophic and bullous variants have also rarely been reported in pediatric population. The exact etiopathogenesis of LP is not known. Immune dysregulation, infections, environmental, and genetic factors have been studied extensively and speculated to play some roles. A wide variety of treatment modalities for LP have been used in adults, and the same are employed in children. There is dearth of randomized controlled trials of evidence based treatments in LP, especially in children probably because of the rarity of the condition, heterogeneity of presentations, and gaps in understanding the exact etiology. This review attempts to present the up to date current information on the epidemiology, etiopathogenesis, clinical features and therapeutic options for lichen planus in children.

Lichen planus (LP), an idiopathic, multifaceted chronic inflammatory disease with a heterogeneous clinical presentation, affects approximately 0.5-1% of the population. The various clinical manifestations of LP fall into three broad categories, namely cutaneous, appendageal, and mucosal, with further subclassification depending on the morphology and distribution patterns of individual lesions. There is mounting evidence that LP has systemic associations, including autoimmune conditions, glucose intolerance, dyslipidemia, and cardiovascular disorders. Cutaneous hypertrophic and mucosal forms of LP are at a heightened risk for malignant transformation. Familiarity with these potential associations in conjunction with long-term follow-up and regular screening could lead to a timely diagnosis and management of concomitant conditions. In addition, the frequent quality of life (QoL) impairment in LP underscores the need for a comprehensive approach including psychological evaluation and support. Several treatment strategies have been attempted, though most of them have not been adopted in clinical practice because of suboptimal benefit-to-risk ratios or lack of evidence. More recent studies toward pathogenesis-driven treatments have identified Janus kinase inhibitors such as tofacitinib, phosphodiesterase-4 inhibitors such as apremilast, and biologics targeting the interleukin-23/interleukin-17 pathway as novel therapeutic options, resulting in a dramatic change of the treatment landscape of LP. This contemporary review focuses on the diagnosis and management of LP, and places emphasis on more recently described targeted treatment options.

Lichen planus (LP) is an idiopathic dermatosis of skin and mucus membrane and exhibits certain variants, of which blaschkoid LP, a rare entity holds an estimated prevalence of 0.24%–0.68%. Its manifestation post-COVID-19 vaccination is being reported in the literature. A case with dermoscopy and histopathology suggestive of LP with morphology as blaschkoid pattern is discussed here.

Liken planus (LP) deride kaşıntılı, morumsu papüller karakterize olup saç, tırnak, mukoza tutulumu da yapabilen etiyolojisi tam olarak bilinmeyen kronik, inflamatuvar bir hastalıktır. Lezyonun şekline, morfolojisine ve anatomik lokalizasyonuna göre LP sınıflaması yapılmaktadır. Burada bu sınıflama içinde ender görülen Blaschko çizgilerine yerleşen Lineer LP olgusu sunmaktayız.

Lichen planus pigmentosus (LPP), an uncommon variant of lichen planus (LP), is characterized by diffuse hyperpigmented dark brown macules in sun-exposed areas. We report an unusual case of LPP with a blaschkoid distribution in an area of radiotherapy for breast cancer. This description is rarely reported. Its pathogeny is poorly understood and suggests an embryological origin by genetic mosaicism and also discusses the immunomodulatory role of radiotherapy in the disease.

Blaschkoid lichen planus

Linear lichen planus (LLP), also known as blaschkolinear or blaschkoid lichen planus, is a rare subtype of lichen planus that presents along the lines of Blaschko. While LLP has been associated with vaccinations, neoplasms, medications, and successive pregnancies, we present a case of LLP following a primary pregnancy. A 29-year-old G1P1 female presented to dermatology for the evaluation of an intensely pruritic, whorled rash confined to her left lower leg that appeared shortly after the birth of her first child. A biopsy of the lesion and subsequent histopathology confirmed the diagnosis of LLP. The patient was treated with topical steroids with minimal response to therapy and declined further treatment.