Reticular erythematous mucinosis--a review

An Atypical Presentation of Reticular Erythematous Mucinosis: A Case Report and Comprehensive Literature Review

Reticular erythematous mucinosis (REM) is a rare form of primary cutaneous mucinosis, often linked to viral infections, inflammatory conditions, ultraviolet radiation, radiotherapy, malignant disorders, or an underlying immune dysfunction. It typically affects middle-aged women and manifests as symmetrical erythematous macules, papules, or plaques that exhibit a reticular and annular configuration, mainly on the midline of the thorax or dorsum. Although these regions represent the most prevalent sites, atypical occurrences have been noted. We report an unusual case of REM in a pediatric female patient with an ongoing history of B-cell acute lymphoblastic leukemia. The physical examination revealed an atypical distribution of REM lesions, symmetrically affecting the gluteal region and proximal thighs. Establishing a definitive diagnosis required a meticulous correlation between clinical, dermoscopic, and histopathologic findings. To our knowledge, this is the first documented case of REM in a patient with acute lymphoblastic leukemia. Our study underlines the importance of including REM in the differential diagnosis of persistent erythematous lesions, particularly in immunocompromised patients or those with a history of malignancy. Furthermore, we provide a comprehensive literature review, emphasizing the etiology, risk factors, pathogenetic mechanisms, diagnostic challenges, and different therapeutic options for REM.

Papulonodular mucinosis: a systematic review on clinicopathologic characteristics, course and treatment options

Papulonodular mucinosis (PNM) is a rare cutaneous mucinosis recognized as a rare variant of lupus erythematosus. There are no large-scale cohort studies characterizing its clinicopathological features or evaluating the effectiveness of various treatment options. This study aimed to review the literature on PNMs to identify its clinical and histological features and treatment outcomes. The search includes studies from the PubMed, Embase, and Cochrane Library databases up to the March 1, 2024. A total of 37 studies, encompassing 44 patients, were included in the review. Of these, 20 were males and 24 females, with a mean age at diagnosis of 34.9 ± 1.92 years. PNM lesions are characterized by generalized papules, plaques, and nodules, and histopathologically, they show abundant mucin deposition throughout the dermis. The temporal relationship between PNM and SLE is variable. There is no evidence that SLE patients with PNM are more prone to organ involvement or increased disease activity. A combination of medical history, clinical features, and histopathological findings is essential for diagnosis; however, misdiagnosis is possible until lupus erythematosus (LE) becomes evident. Hydroxychloroquine and systemic glucocorticoids are the current mainstays of treatment for PNM, with most patients achieving partial or complete remission.

[Translated article] Reticulate Skin Lesions: Practical Color-Based Algorithm for Initial Clinical Assessment

Reticular patterns are observed in a great variety of skin diseases. While these morphologic patterns are often highly distinctive, they are seldom discussed or studied in clinical contexts or recognized as a diagnostic category in their own right. Diseases presenting with reticulate skin lesions have multiple etiologies (tumors, infections, vascular disorders, inflammatory conditions, and metabolic or genetic alterations) and can range from relatively benign conditions to life-threatening ones. We review a selection of these diseases and propose a clinical diagnostic algorithm based on predominant coloring and clinical features to aid in their initial assessment.

Reticulate Skin Lesions: Practical Color-Based Algorithm for Initial Clinical Assessment

Reticular patterns are observed in a great variety of skin diseases. While these morphologic patterns are often highly distinctive, they are seldom discussed or studied in clinical contexts or recognized as a diagnostic category in their own right. Diseases presenting with reticulate skin lesions have multiple etiologies (tumors, infections, vascular disorders, inflammatory conditions, and metabolic or genetic alterations) and can range from relatively benign conditions to life-threatening ones. We review a selection of these diseases and propose a clinical diagnostic algorithm based on predominant coloring and clinical features to aid in their initial assessment.

Reticular erythematous mucinosis: Relationship between its dermoscopic and histopathological findings

Key Clinical Message

In reticular erythematous mucinosis, (1) the presence of dotted vessels and (2) uniform, structureless, yellowish-white spots, and patches on dermoscopy correspond to histopathological findings of (1) vessels at the tips of the dermal papillae and (2) thickening and rupture of the collagen and fiber bundles with mucin deposition, respectively.

Abstract

Reticular erythematous mucinosis is a rare form of skin mucinosis that primarily affects middle-aged women, typically appearing as papules and plaques in the upper chest or midline of the back. Here, we report the case of a 75-year-old woman with skin papules and plaques left untreated for 8 years. A gross skin examination was followed by histopathological and dermoscopic examinations. The main dermoscopic findings were (1) dotted vessels and (2) uniform structureless yellowish-white spots and patches. The corresponding histopathological findings were (1) vessels at the tips of the dermal papillae and (2) thickening and rupturing of the collagen and fiber bundles with mucin deposition, respectively. Laboratory investigations revealed normal results, ruling out various autoimmune disorders. REM was diagnosed based on these findings. The study presents relevant evidence-based findings in dermatology and cutaneous pathology as it is the first description of REM using dermoscopy. Dermoscopic diagnosis without other unnecessary tests would benefit both the clinician and the patient.

Reticular Erythematous Mucinosis in an African Woman with HIV Infection: Case Report and Literature Review

Reticular erythematous mucinosis is a rare and persistent form of primary idiopathic mucinosis, often referred to as plaque-like cutaneous mucinosis or midline mucinosis. It presents with reticulate patches or erythematous plaques with predilection for the anterior and posterior trunk. Affected patients are frequently asymptomatic. Pruritus or burning sensations were reported after exposure to the sun. The aetiology remains obscure; its pathogenesis is poorly understood, particularly in immunocompromised patients such as HIV-infected patients. The disease associations are not uniformly documented. Antimalarial agents significantly improve and shorten the course of the disease. We report a case of a 31-year-old African woman with underlying HIV infection who displayed the classical clinical and histological features of reticular erythematous mucinosis. This condition is rare among the HIV-infected patients, particularly in those of African descent, in whom lichen myxoedematosus/scleromyxoedema variants and acral persistent papular mucinoses were most frequently reported. The higher incidence of photosensitivity in HIV-infected individuals including the patients with skin of colour may play a potential role in reticular erythematous mucinosis. Its relationship with lupus erythematosus and photosensitivity in the context of HIV infection is discussed. To the best of our knowledge, this is the first reported case of reticular erythematous mucinosis in an African HIV-infected patient. This case highlights the need for diagnostic awareness in cases presenting with erythematous plaques and patches in a net-like pattern developing on the midline and sun-exposed areas of the trunk.

Reticular Erythematous Mucinosis: Exclusive Involvement of the Axillary Region

Reticular erythematous mucinosis is a primary cutaneous mucinosis characterized by the presence of erythematous macules, papules, or plaques coalescing into a reticular pattern that typically involves the midline of the chest or back in middle-aged women. Because of this peculiar location, it is also called midline mucinosis. Although atypical disease localizations have been described in the literature, these have always been accompanied by midline involvement. We report a case of reticular erythematous mucinosis with exclusive involvement of the axillary region.

A case report of a localized reticular erythematous mucinosis like eruption of the lower legs mimicking cutaneous larvae migrans

Reticular erythematous mucinosis is an uncommon type of cutaneous mucinosis. Typically, reticular erythematous mucinosis affects middle-aged women and usually appears as papules and plaques on the mid-upper trunk. Histologically, biopsies of reticular erythematous mucinosis reveal increased deposition of dermal mucin and perivascular lymphocytic inflammation. Infrequently, reticular erythematous mucinosis has been reported in males and in atypical locations other than the trunk. In these instances, reticular erythematous mucinosis can present a diagnostic challenge clinically and histologically. This case describes the clinical and histologic findings of a localized variant of reticular erythematous mucinosis in a 65-year-old male patient.

Plaque-like cutaneous mucinosis of childhood

A healthy 10-year-old boy presented with plaque-like cutaneous mucinosis (PCM) on his back. Cutaneous biopsy was followed by progressive resolution of the skin lesion. Pediatric PCM could differ clinically from the adult form. However, more cases are necessary to draw conclusions.

Reticular erythematous mucinosis: Literature review and case report of a 24-year-old patient with systemic erythematosus lupus

Reticular erythematous mucinosis (REM) was first described 50 years ago, but only around 100 case reports in English have been published. Its relation with other inflammatory skin disorders is still being debated. We report a case of REM, including the clinical and histopathological findings. Also, a systematic review of 94 English-language reported cases is provided. The described criteria for clinical and histopathological diagnosis are highlighted in order to REM can be confidently diagnosed.

Lupus erythematosus tumidus: clinical perspectives

Lupus erythematosus tumidus (LET) is an uncommon and photosensitive inflammatory skin disorder which is characterised by erythematous urticarial plaques. In the last 20 years, extensive research on clinical and histological aspects of the disease have led to a better characterization of this nosological entity and to differentiate it from other similar or related diseases. Today, LET is considered as a separate subtype of cutaneous lupus erythematosus (CLE) with a benign, intermittent clinical course (intermittent CLE, ICLE) and only rarely associated with systemic lupus erythematosus (SLE).

Tinea Imbricata: An Overview

BACKGROUND

Tinea imbricata is a chronic superficial mycosis caused mainly by Trichophyton concentricum. The condition mainly affects individuals living in primitive and isolated environment in developing countries and is rarely seen in developed countries. Physicians in nonendemic areas might not be aware of this fungal infection.

OBJECTIVE

To familiarize physicians with the clinical manifestations, diagnosis, and treatment of tinea imbricata.

METHODS

A PubMed search was completed in Clinical Queries using the key terms "Tinea imbricata" and "Trichophyton concentricum". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, reviews, and case reports. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

The typical initial lesions of tinea imbricata consist of multiple, brownish red, scaly, pruritic papules. The papules then spread centrifugally to form annular and/or concentric rings that can extend to form serpinginous or polycyclic plaques with or without erythema. With time, multiple overlapping lesions develop, and the plaques become lamellar with abundant thick scales adhering to the interior of the lesion, giving rise to the appearance of overlapping roof tiles, lace, or fish scales. Lamellar detachment of the scales is common. The diagnosis is mainly clinical, based on the characteristic skin lesions. If necessary, the diagnosis can be confirmed by potassium hydroxide wet-mount examination of skin scrapings of the active border of the lesion which typically shows short septate hyphae, numerous chlamydoconidia, and no arthroconidia. Currently, oral terbinafine is the drug of choice for the treatment of tinea imbricata. Combined therapy of an oral antifungal agent with a topical antifungal and keratolytic agent may increase the cure rate.

CONCLUSION

In most cases, a spot diagnosis of tinea imbricata can be made based on the characteristic skin lesions consisting of scaly, concentric annular rings and overlapping plaques that are pruritic. Due to popularity of international travel, physicians involved in patient care should be aware of this fungal infection previously restricted to limited geographical areas.

Reticular telangiectatic erythema: case report and literature review

Background:

Reticular telangiectatic erythema is a benign cutaneous reaction that may occur in patients who have received a subcutaneous implantable cardioverter-defibrillator. Reticular telangiectatic erythema is characterized by asymptomatic telangiectasias, blanchable erythematous patches, or both overlying and/or adjacent to the subcutaneous implantable cardioverter-defibrillator.

Purpose:

We describe a man who developed reticular telangiectatic erythema after receiving a subcutaneous implantable cardioverter-defibrillator and review the salient features of this condition. We also summarize the conditions that can mimic reticular telangiectatic erythema.

Materials and methods:

The features of a man with reticular telangiectatic erythema are presented and the literature on reticular telangiectatic erythema is reviewed.

Results:

Our patient developed reticular telangiectatic erythema within one month of subcutaneous implantable cardioverter-defibrillator insertion. The subcutaneous manifestations were asymptomatic. The patient concurred to have periodic clinical follow up and his condition will be monitored for any changes.

Conclusion:

Reticular telangiectatic erythema is a benign condition characterized by the development of erythema, telangiectasia, or both following insertion of a subcutaneous implantable cardioverter-defibrillator. Other subcutaneous implantable cardioverter-defibrillator-related side effects, such as pressure dermatitis and contact dermatitis, can mimic the condition. Reticular telangiectatic erythema can also be observed following insertion of other devices or, rarely, in the absence of inserted devices. Local microcirculatory changes and subcutaneous implantable cardioverter-defibrillator-related obstruction of blood flow have been suggested as possible mechanisms of pathogenesis. The diagnosis can usually be established by clinical presentation. Therefore, patch testing can usually be omitted. Reticular telangiectatic erythema is typically asymptomatic and thus removal of the device is not required.

Can biologic treatment induce cutaneous focal mucinosis?

Skin mucinosis is a rare skin disease which clinically manifests as firm papules and waxy nodules. We report a case of a 66-year-old female psoriatic patient who developed skin mucinosis during biological therapy. Because of a previous lack of response to the local and conventional systemic treatment of psoriasis, the patient received biological therapy (infliximab from June 2008 to May 2009 – initial clinical improvement and loss of treatment effectiveness in the 36^th week of the therapy; adalimumab from June 2009 to January 2010 – lack effectiveness; ustekinumab from March 2012 to the present). Throughout 2 months we observed a manifestation of the skin mucinosis as well-demarcated, yellow and brown, papulo-nodular lesions of 5–10 mm in diameter, localized on the back. Histopathological examination with alcian blue staining demonstrated mucin deposits in the dermis. On the basis of clinical and histopathological findings, the diagnosis of cutaneous focal mucinosis was established. We present the case because of the extremely rare occurrence of the disease. Scarce literature and data suggest that there is an association between focal mucinosis and thyroid dysfunction, as well as possible adverse effects of biological therapy with TNF-α antagonists.

Reticular erythematous mucinosis: a review of patients' characteristics, associated conditions, therapy and outcome in 25 cases

BACKGROUND

Reticular erythematous mucinosis (REM) is an uncommon disease, the nosology and specific characteristics of which are controversial because most reports deal with single cases or small series.

OBJECTIVES

To describe the characteristics of patients with REM regarding demographics, clinical and pathological features, comorbidities, treatment and course.

METHODS

A retrospective and prospective study was conducted on 25 patients diagnosed with REM in the setting of university-affiliated dermatology departments and dermatopathology centres.

RESULTS

Of the 25 patients with REM, 16 were women (sex ratio 2 : 1) and the mean age was 46 years. The roles of sun exposure and oral contraceptives were ambiguous. Associated diseases included hypertension (n = 4), malignancies (n = 3), autoimmune diseases (n = 3) and Borrelia infection (n = 1). Immunological studies (including serology and direct immunofluorescence) were noncontributory. The response to antimalarial treatment was good in > 80% of cases. Worsening or recurrence of the lesion after treatment discontinuation, or in the course of the disease, occurred in 31% of patients.

CONCLUSIONS

We present the largest REM case series to date. The reticular pattern with involvement of the midline of the chest and back, the predilection for middle-aged women, the controversial relationship with photosensitivity and the possible association with other conditions such as malignancies and thyroid dysfunctions are the main characteristics that makes REM a recognizable disease.

Reticular erythematous mucinosis: histopathological and immunohistochemical features of 25 patients compared with 25 cases of lupus erythematosus tumidus

BACKGROUND AND OBJECTIVES

Reticular erythematous mucinosis (REM) and lupus erythematosus tumidus (LET) share similarities. However, to our knowledge no study extensively compared the histological features of these two conditions. The aim of this study is to compare the histological and immunohistochemical features of REM and LET.

METHODS

We evaluated epidermal thickness, hyperkeratosis, dermo-epidermal junction changes, interstitial mucin deposition, vessel dilatation and pattern, type and density of the inflammatory infiltrate in 25 cases of REM and LET. Anti-CD3, anti-CD20, anti-CD68, anti-CD4, anti-CD8, anti-CD123, anti-CD2AP, anti-IgG and anti-C3 antibodies were tested in a subset of patients.

RESULTS

Both diseases are characterized by perivascular dermal infiltrates of lymphocytes mainly CD4+ positive and increased dermal mucin. However, REM tended to show more scattered and more superficial lymphocytes with more superficial mucin and to have less frequent immunoglobulin and complement depositions along the dermo-epidermal junction. Plasmacytoid dendritic cells (PDCs) were less represented in REM, and were mainly found as single cells differently from LET.

CONCLUSIONS

REM and LET present some differences in the infiltrate, including PDCs, the mucin deposition and the immunoreactant deposition at the dermo-epidermal junction that justify the distinction of the two diseases and suggest different pathogenetic mechanisms.

Correlations between skin lesions induced by anti-tumor necrosis factor-α and selected cytokines in Crohn's disease patients

AIM: To investigate the correlation between the appearance of skin lesions and concentration of interleukin (IL)-17A, IL-23 and interferon-γ (IFN-γ) in Crohn’s disease (CD) patients during anti-tumor necrosis factor-α (TNF-α) therapy

METHODS: A prospective study included 30 adult patients with CD of Caucasian origin (19 men and 11 women; mean age ± SD 32.0 ± 8.6 years) during biological therapy with anti-TNF-α antibodies from January 2012 to March 2013. Eighteen patients were treated with infliximab, seven with adalimumab and five with certolizumab. Inclusion criteria were exacerbation of the underlying disease, Crohn’s Disease Activity Index over 300 and the ineffectiveness of previously used non-biological therapies. Patients with a history of psoriasis, atopic dermatitis and other autoimmune skin lesions were excluded from the study. The control group consisted of 12 healthy subjects. A diagnostic survey was carried out, blood tests and careful skin examination were performed, and the serum levels of IL-17, IL-23 and IFN-γ were measured using an enzyme-linked immunosorbent assays technique. Dermatoses that have developed in the course of biological therapy in patients who had no pre-existing skin lesions of similar character were qualified as skin lesions induced by anti-TNF-α therapy.

RESULTS: Skin manifestations occurred in 18 of CD patients during the anti-TNF-α therapy (60%), in the average time of 10.16 ± 3.42 mo following the beginning of the 52-wk treatment cycle. Skin lesions observed in CD patients during biological therapy included psoriasiform lesions (44.4%), and eczema forms lesions (22.2%). In CD patients with drug induced skin lesions significantly higher levels of hemoglobin (13.3 ± 1.5 g/dL vs 10.8 ± 1.9 g/dL, P = 0.018) and hematocrit (39.9% ± 4.5% vs 34.3% ± 5.4%, P = 0.01), as well as a significantly lower level of platelets (268 ± 62 × 10³/μL vs 408 ± 239 × 10³/μL, P = 0.046) was observed compared with CD patients without skin manifestations. The concentrations of IL-17A and IL-23 in CD patients with skin lesions developed under anti-TNF-α therapy were significantly higher compared to those in patients without lesions (IL-17A: 39.01 ± 7.03 pg/mL vs 25.71 ± 4.90 pg/mL, P = 0.00004; IL-23: 408.78 ± 94.13 pg/mL vs 312.15 ± 76.24 pg/mL, P = 0.00556).

CONCLUSION: Skin lesions in CD patients during biological therapy may result from significantly increased concentrations of IL-17A and IL-23, which are strongly associated with TNF-α/Th1 immune pathways.