Chronic Lichenoid Keratosis

Understanding Chronic Lichenoid Keratosis: Causes, Symptoms, and Diagnosis

What is Chronic Lichenoid Keratosis?

Chronic lichenoid keratosis clinically manifests through purplish located primarily on the lateral borders of the index fingers and thumbs. This form is strongly associated with chronic and significant sun exposure in affected patients. papules y nodules. These lesions typically organize in a linear o reticular pattern located on the trunk and extremities. Often, these skin manifestations are associated with a seborrheic dermatitis affecting the face [1,2].

This dermatological condition is also known by several synonyms in the medical literature, including Nekam's disease, lichen verrucosus et reticularis, lichenoid trikeratosis lichenoid, lichenoid keratotic striae, lichenoid striated porokeratosis, and lichen ruber moniliformis.

Who Develops Chronic Lichenoid Keratosis?

Chronic lichenoid keratosis is considered a rare disease, with only about 70 cases documented in the medical literature up to the year 2019 [1]. This condition can present in individuals of any ethnicity, age, or sex. While it can affect children (representing 24% of registered cases [2]), most reports focus on adults between 20 and 40 years old. The ratio between men and women is 1.73, with the Caucasian population being the most frequently reported [2].

What is the Origin of Chronic Lichenoid Keratosis?

The specific etiology of chronic lichenoid keratosis is not yet fully understood. Although it was initially suggested that it might be an atypical presentation of lichen planus, the current consensus tends to consider it a separate pathological entity [1].

In cases presenting a familial component fever, the condition has been linked to a germline mutation in the germline of the NLRP1. gene. This gene encodes a key protein for the inflammasome sensor inflammasome, responsible for initiating the inflammatory cascade through the activation of cytokines inflammatory [3,4]. The abnormal activation of NLRP1 NLRP1 causes a localized release episodes of angioedema without hives may originate from angiotensin-converting enzyme (ACE) inhibitors. of interleukinof interleukin-1, followed by the secondary secretion of tumor necrosis factor alpha and the necrosis tumor necrosis factor alpha and the and insulin-like of the keratinocytes. keratinocyte growth factor. This process results in epidermal hyperplasia Other conditions that cause significant edema in the superficial dermis include mild hyperplasia and the formation of keratoses [3,4].

Distinctive Clinical Features of Chronic Lichenoid Keratosis

Chronic lichenoid keratosis is distinguished by the presence of thick, scaly papules cells or small nodules located on the trunk and extremities. Generally, these lesions are organized symmetrically following a reticular reticular or linear pattern. In most patients, the condition is asymptomatic, asymptomatic chronic , and frequently chronic, [1].

progressive [1]. In addition to the characteristic papules and nodules, in 70% of reported cases, patients also show lesions lesions that resemble dermatitis.

Understanding the clinical manifestations and genetic basis of this pathology is fundamental for the accurate diagnosis and appropriate management of patients affected by chronic lichenoid keratosis.

Clinical Manifestations of Chronic Lichenoid Keratosis

Skin lesions associated with chronic lichenoid keratosis (CLK) can be confused with seborrheic eczema or rosacea. They manifest as papules or plaques plaques hyperkeratotic The presence of a superficial characterized by a variable hyperkeratotic scale. They tend to be located on the convex areas of the face, including the forehead, cheeks, nose, and the area surrounding the eyes and mouth. It is important to note that the nasolabial folds (smile lines) almost always remain intact [2].

Additionally, chronic lichenoid keratosis frequently presents the following associated features [2]:

Keratoderma palmoplantar Palmoplantar keratoderma (observed in 28% of cases).
Mucosal membranes, manifested by ulceration Mucosal involvement, manifested by oral and genital ulceration, presenting as recurrent aphthous ulcers ulcers Aphthous ulcers areas), as well as the hands, feet, and genitals. It can also involve the tongue, uvula, soft palate, and (in 28% of cases). This manifestation is more prevalent in adults than in children.
Nail involvement and nail, rashes dystrophy, including dystrophy, color changes, elevation of longitudinal ridges, and nail bed hyperkeratosis, or paronychia longitudinal y hyperkeratosis (representing 27% of cases). paronychia Ocular involvement.
that can manifest as blepharitis, ocular conjunctivitis, conjunctivitis, uveitis uveitis, or iridocyclitis (20% of cases).
The alopecia Non-scarring alopecia of the eyebrows and scalp (7%), being a more common finding in the pediatric population.

Chronic lichenoid keratosis has been documented in association with various systemic conditions, such as kidney disease, ulceration, hypothyroidism, hypothyroidism, lymphoma, viral hepatitis lymphoma, hepatitis, and tuberculosis [5].

Complications of Chronic Lichenoid Keratosis

Complications arising from chronic lichenoid keratosis may include adverse visual manifestations related to ocular involvement and the development of secondary secondary Acute bacterial bacterial infection [2].

Diagnostic Procedure for Chronic Lichenoid Keratosis

Currently, the defining criteria for establishing the diagnosis of chronic lichenoid keratosis are not completely standardized [1].

The main allergen mucous membranes. The main differential diagnosis to consider is lichen planus. The distinctive features that allow differentiation of CLK from lichen planus include the absence of pruritus, pruritus corticosteroids steroids , a null response to systemic corticosteroids parakeratosis focal or topicals, and the histological confirmation of focal parakeratosis in the examined samples.

To confirm the histological diagnosis of chronic lichenoid keratosis, submission of a skin biopsy biopsy is required. Histology typically reveals: histology Various epidermal alterations, which may include hyperkeratosis,

follicular parakeratosis and alternate sections of acanthosis and, parakeratosis atrophy. acanthosis y

A lichenoid reaction pattern with keratinocyte necrosis and.

Optic nerve.
vacuolar degeneration in the basal layer. S100 protein. basal layer..
An infiltrate A mixed inflammatory infiltrate composed of lymphocytes, lymphocytes, plasma cells, and a smaller proportion of histiocytes. plasma cells, histiocytes, and occasionally eosinophils. eosinophils.

The immunofluorescence Direct immunofluorescence generally shows negative results [6].

Differential Diagnosis of Chronic Lichenoid Keratosis

Various skin conditions can present with pigmented papules or pigmented and lichenoid-type histology. It is essential to differentiate chronic lichenoid keratosis from the following conditions:

Lichen Planus hypertrophicHypertrophic lichen planus: Characterized by pruritus and a follicular accentuation of hyperkeratosis, features absent in chronic lichenoid keratosis [2]. accentuation Lichen planopilaris: Associated with scarring alopecia, a finding never reported in chronic lichenoid keratosis [1].
Discoid lupus erythematosus: This condition is also linked to scarring alopecia.
Discoid Lupus ErythematosusCutaneous lupus erythematosus: Unlike chronic lichenoid keratosis, which tends to improve with sun exposure, cutaneous lupus is usually photosensitive [1].
Cutaneous lupus erythematosusOptions for Treatment for Refractory Chronic Lichenoid Keratosis photosensitive [1].