Clinical and histologic features of Mycoplasma pneumoniae-related erythema multiforme: A single-center series of 33 cases compared with 100 cases induced by other causes

Diffusive mediator feedbacks control the health-to-disease transition of skin inflammation

The spatiotemporal dynamics of inflammation provide vital insights into the understanding of skin inflammation. Skin inflammation primarily depends on the regulatory feedback between pro- and anti-inflammatory mediators. Healthy skin exhibits fading erythema. In contrast, diseased skin exhibits expanding erythema with diverse patterns, which are clinically classified into five types: circular, annular, arcuate, gyrate, and polycyclic. Inflammatory diseases with expanding erythema are speculated to result from the overproduction of pro-inflammatory mediators. However, the mechanism by which feedback selectively drives the transition from a healthy fading erythema to each of the five types of diseased expanding erythema remains unclear. This study theoretically elucidates the imbalanced production between pro- and anti-inflammatory mediators and prospective treatment strategies for each expanding pattern. Our literature survey showed that eleven diseases exhibit some of the five expanding erythema, thereby suggesting a common spatiotemporal regulation underlying different patterns and diseases. Accordingly, a reaction-diffusion model incorporating mediator feedback reproduced the five observed types of diseased expanding and healthy fading patterns. Importantly, the fading pattern transitioned to the arcuate, gyrate, and polycyclic patterns when the productions of anti-inflammatory and pro-inflammatory mediators were lower and higher, respectively than in the healthy condition. Further depletion of anti-inflammatory mediators caused a circular pattern, whereas further overproduction of pro-inflammatory mediators caused an annular pattern. Mechanistically, the bistability due to stabilization of the diseased state exhibits circular and annular patterns, whereas the excitability exhibits the gyrate, polycyclic, arcuate, and fading patterns as the threshold of pro-inflammatory mediator concentration relative to the healthy state increases. These dynamic regulations of diffusive mediator feedback provide effective treatment strategies for mediator production wherein skins recover from each expanding pattern toward a fading pattern. Thus, these strategies can estimate disease severity and risk based on erythema patterns, paving the way for developing noninvasive and personalized treatments for inflammatory skin diseases.

Reality of drug-induced erythema multiforme: A French pharmacovigilance study

BACKGROUND

Since the 2002 SCAR study, erythema multiforme (EM), a post-infectious disease, has been distinguished from Stevens-Johnson syndrome (SJS), drug-induced. Nevertheless, EM cases are still reported in the French pharmacovigilance database (FPDB).

OBJECTIVES

To describe EM reported in the FPDB and to compare the quality and the characteristics of the reports.

METHODS

This retrospective observational study selected all EM cases reported in the FPDB over two periods: period 1 (P1, 2008-2009) and period 2 (P2, 2018-2019). Inclusion criteria were 1) a diagnosis of clinically typical EM and/or validated by a dermatologist; 2) a reported date of onset of the reaction; and 3) a precise chronology of drug exposure. Cases were classified confirmed EM (typical acral target lesions and/or validation by a dermatologist) and possible EM (not-otherwise-specified target lesions, isolated mucosal involvement, doubtful with SJS). We concluded possible drug-induced EM when EM was confirmed, with onset ranging from 5 to 28 days without an alternative cause.

RESULTS

Among 182 selected reports, 140 (77%) were analyzed. Of these, 67 (48%) presented a more likely alternative diagnosis than EM. Of the 73 reports of EM cases finally included (P1, n=41; P2, n=32), 36 (49%) had a probable non-drug cause and 28 (38%) were associated with only drugs with an onset time ≤4 days and/or ≥29 days. Possible drug-induced EM was retained in 9 cases (6% of evaluable reports). Etiological work-up was more often performed in period 2 than 1 (53.1% vs 29.3%, P=0.04), and the time to onset from 5 to 28 days was more frequent in period 2 (59.2% vs 40%, P=0.04).

CONCLUSIONS

This study suggests that possible drug-induced EM is rare. Many reports describe "polymorphic" rashes inappropriately concluded as EM or post-infectious EM with unsuitable drug accountability subject to protopathic bias.

Reactive infectious mucocutaneous eruption due to COVID-19 with erythema-multiforme-like lesions and myeloid cells

Reactive infectious mucocutaneous eruption (RIME) is a recently described entity in which there is prominent mucositis, most commonly involving the oral and urogenital mucosa, secondary to a variety of pathogens. There is typically minimal cutaneous involvement in RIME. This contrasts with erythema multiforme (EM) in which characteristic targetoid lesions predominate, usually in isolation (EM minor), but in a subset of cases, with severe mucositis (EM major). While the histopathologic features of RIME have not been as well defined, those of EM are characterized by epidermal apoptosis and interface dermatitis with lymphocytes making up the predominant cell type. We report a unique case of RIME in a 16-year-old male with COVID-19 characterized by significant mucositis involving the oral and genital mucosa, as well as numerous targetoid lesions on the trunk and extremities. Histopathologically, there was an inflammatory infiltrate obscuring and disrupting the epidermal interface, associated with epidermal necrosis, and blister formation. The infiltrate was composed of cells with irregular, non-segmented and elongate nuclei, with myeloid and histiocytoid cytomorphology. The cells were positive for myeloperoxidase, CD68, and CD163 (subset) suggesting myeloid lineage. RIME is a rarely reported COVID-19-related eruption, and targetoid lesions and myeloid interface reactions have not been described with RIME.

Annular drug eruptions

Cutaneous adverse drug reactions are undesirable cutaneous changes caused by medications. Drug eruptions can mimic a wide range of dermatoses that include exanthematous (morbilliform), urticarial, pustular, bullous, papulosquamous, or granulomatous lesions, and sometimes these eruptions may present with annular, polycyclic, or polymorphous configurations. The correct identification of a cutaneous drug eruption depends on a high index of suspicion, detailed medication exposure history, chronologic evaluation of the causal relationships between drug exposures and eruptions, and the exclusion of other infectious or idiopathic diseases. Most drug eruptions are annoying but self-limited, usually resolving after the withdrawal of the causative agents. Rarely, patients have severe cutaneous adverse reactions, such as Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug reaction with eosinophilia and systemic symptoms (DRESS), which are potentially lethal adverse drug reactions that involve the skin and mucous membranes and may also damage internal organs. Prompt recognition of the alarming signs of severe cutaneous adverse reactions and providing adequate treatment may thus be life-saving. We present the main clinical presentations, histopathology, possible implicated medications, and treatment of cutaneous adverse drug reactions that can present in annular configurations.

Immunological aspects of COVID-19 related skin manifestations: revisiting pathogenic mechanism in the light of new evidence

The newly emerged coronavirus disease 2019 (COVID‐19), induced by a novel strain of the coronavirus family, named severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), is a rapidly spreading global threat. This virus affects a fair number of tissues in the human body by availing itself of potential target receptors like Angiotensin‐Converting Enzyme 2 (ACE2). Presenting with diverse clinical manifestations, COVID‐19 has raised the urge for extensive research in different medical fields, including dermatology. Developing a comprehensive knowledge of cutaneous manifestations is highly important as it can help us in early diagnosis and better management of the ongoing pandemic. The dermatological presentations of COVID‐19 are classified into main categories of vascular and non‐vascular (exanthematous) patterns. Though not yet fully confirmed, the pathogenesis of these cutaneous presentations has been suggested to be more related to the overactivation of the immune system. In this review, we discuss in detail the clinical features of the diverse skin lesions in COVID‐19 patients and the imperative role of the immune system in their pathogenesis and development. Furthermore, we will discuss the reasons behind the accentuation of skin lesions in COVID‐19 compared to the same virus family predecessors.

Severe blistering eruptions induced by immune checkpoint inhibitors: a multicentre international study of 32 cases

Among dermatologic adverse events induced by immune checkpoint inhibitors (ICI), bullous life-threatening reactions are rare. To better define the clinical and histological features, treatment, and prognosis of ICI-related severe blistering cutaneous eruptions. This retrospective case series was conducted between 2014/05/15 and 2021/04/15 by the dermatology departments of four international registries involved in drug reactions. Inclusion criteria were age ≥18 years old, skin eruption with blisters with detachment covering ≥1% body surface area and at least one mucous membrane involved, available pictures, and ICI as suspect drug. Autoimmune bullous disorders were excluded. Each participant medical team gave his own diagnosis conclusion: epidermal necrolysis (EN), severe lichenoid dermatosis (LD), or unclassified dermatosis (UD). After a standardized review of pictures, cases were reclassified by four experts in EN or LD/UD. Skin biopsies were blindly reviewed. Thirty-two patients were included. Median time to onset was 52 days (3-420 days). Cases were originally diagnosed as EN in 21 cases and LD/UD in 11 cases. After review by experts, 10/21 EN were reclassified as LD/UD. The following manifestations were more frequent or severe in EN: fever, purpuric macules, blisters, ocular involvement, and maximal detachment. Most patients were treated with topical with or without systemic corticosteroids. Eight patients (25%) died in the acute phase. The culprit ICI was not resumed in 92% of cases. In three patients, another ICI was given with a good tolerance. Histology did not reveal significant differences between groups. Severe blistering cutaneous drug reactions induced by ICI are often overdiagnosed as EN. Consensus for management is pending.

EasyNAT MP Assay: A Simple, Rapid, and Low-Cost Method to Detect Mycoplasma pneumoniae Using Cross-Priming Amplification Technology

Background

Mycoplasma pneumoniae (MP) is the most common pathogen of atypical pneumonia and the main cause of community-acquired pneumonia (CAP) in infants and older adults. This study aimed at investigating a method based on the cross-priming amplification (CPA) technique for the rapid detection of MP in clinical specimens collected from patients with CAP.

Methods

The sensitivity and specificity of the EasyNAT MP assay were determined. Oropharyngeal swab specimens were collected from 162 in-patients of Hangzhou First People’s Hospitals from January 2018 to December 2020. The patients were aged between 1 and 15 years with symptoms, signs, and chest radiographs consistent with CAP. This study evaluated the presence of MP in the clinical specimens using the EasyNAT method and the conventional fluorescence quantitative PCR technique.

Results

The limit of detection using the EasyNAT MP assay was 500 copies/mL, while the test results of the other 13 common pathogens causing CAP or colonizing in the upper respiratory tract showed no cross-reactivity. Of 162 specimens, EasyNAT MP gave a positive indication in 82 specimens. Compared with conventional fluorescence quantitative PCR, the positive coincidence rate and the negative coincidence rate of EasyNAT MP was found to be 100.00% and 97.56%, respectively. Of the 82 specimens, two specimens were determined to be negative by the conventional fluorescence quantitative PCR, but were positive for EasyNAT MP. The two samples were re-extracted and confirmed to be positive by conventional fluorescence quantitative PCR.

Conclusion

EasyNAT MP is suitable as an initial test for MP diagnosis due to its simplicity, low turnaround time, and high sensitivity and specificity.

Evaluation of Thalidomide Treatment of Patients With Chronic Erythema Multiforme: A Multicenter Retrospective Cohort Study

Importance

Erythema multiforme (EM) may become long term, with a recurrent or persistent course. First-line treatment for chronic EM is valaciclovir. There is no consensus for selection of second-line treatment of chronic EM.

Objective

The aim of this study was to assess the effectiveness of treatment with thalidomide for patients with chronic EM.

Design, Setting, and Participants

In this retrospective national multicenter cohort study, among 68 French hospital dermatology departments contacted by e-mail, 10 reported having eligible cases. All adults aged 18 years or older under dermatology care for chronic EM (including recurrent and persistent forms) who had received thalidomide between 2010 and 2018 were included. Analyses were conducted from June 24, 2019, to December 31, 2019.

Main Outcomes and Measures

The primary outcome was the proportion of patients who did not experience an EM flare within 6 months of initiating thalidomide treatment for recurrent EM or with complete clearance at 6 months for persistent EM (complete remission).

Results

Overall, 35 patients with chronic EM (median [range] age, 33 [15-65] years; 20 [57%] female) experienced failure of at least 1 previous treatment prior to initiating treatment with thalidomide. After 6 months of continuous thalidomide treatment, 23 (66%) were in complete remission, 5 (14%) had stopped the treatment, and 7 (20%) experienced at least 1 flare. The median (IQR) initial dose followed by remission was 50 (50-100) mg/d. Main adverse effects were asthenia (16 [46%]) and neuropathy (14 [40%]). Twenty-five (71%) of patients stopped thalidomide treatment after a median (IQR) of 12 (8-20) months owing to lack of effect (7/25 [28%]), neuropathy or another adverse effect (14/25 [56%]), or long-term complete remission (4/25 [16%]). Low-dose thalidomide, less than 50 mg every other day was sufficient in 9 of 23 (39%) of responders and was associated with less neuropathy and longer treatment duration.

Conclusions and Relevance

In this cohort study, second-line therapy with thalidomide was associated with complete remission in two-thirds of the 35 patients with chronic EM. However, adverse events were a common cause of thalidomide withdrawal. In the long term, dose reduction when possible may allow for continuation by improving tolerance.

Chronic Spontaneous and Inducible Urticaria Associated With Mycoplasma pneumoniae Infection

Acute childhood urticaria is a common disorder that has been associated with infections. In a few children, it may last for more than six weeks, thereafter it is characterized as chronic urticaria (CU). We report two cases, one suffering from chronic spontaneous urticaria and one chronic inducible urticarias (dermographism and cold urticaria). Both children had concomitant respiratory symptoms that were associated with Mycoplasma pneumoniae (MP) infection. Urticarias' symptoms and signs were refractory to regular antihistamines dose but showed marked improvement or complete resolution following clarithromycin administration. CU response to antibiotics pointed strongly to a potential causative role of MP in the pathogenesis of chronic spontaneous and chronic inducible urticarias. It is not clear if MP was the etiopathogenic cause or just the trigger. Nevertheless, refractory to antihistamines urticarias associated with MP infection may respond to antibiotics, which should be considered as an alternative therapeutic approach.

Mycoplasma pneumoniae-induced rash and mucositis: A case report

Mycoplasma pneumoniae-induced rash and mucositis (MIRM) is a recently defined clinical entity characterized by pneumonia caused by M. pneumoniae with associated mucositis and frequent cutaneous lesions of a characteristic pattern. Although often similar in presentation, MIRM has distinct clinical and histologic features that are different from erythema multiforme and Stevens-Johnson syndrome/toxic epidermal necrolysis. We report a case of MIRM in a nine-year-old boy.

Mycoplasma Pneumoniae-Induced Rash and Mucositis: A Systematic Review of the Literature

INTRODUCTION

Mycoplasma pneumoniae (MP) is a common respiratory pathogen that can result in community-acquired pneumonia (CAP). Approximately 25% of patients diagnosed with MP experience extrapulmonary manifestations. Mycoplasma-induced rash and mucositis (MIRM) was coined as a unique disease process in 2014. MIRM has prominent mucositis with or without a characteristic vesiculobullous and/or atypical targetoid eruption. Appropriate identification of this disease is important because it has a milder disease course with low rates of sequelae, and lower mortality compared to Stevens-Johnson syndrome, erythema multiforme, and toxic epidermal necrolysis. The objective of this systematic review was to examine the English literature on Mycoplasma Pneumonia-induced rash and mucositis since the establishment of its diagnosis in 2014.

METHODS

The following online databases were used to identify appropriate studies that met the established inclusion and exclusion criteria: Pubmed, Cochrane, MedLine, Health Evidence, EPPI center, Allied Health Evidence. The following MesH search terms were used to further identify articles; "Mycoplasma pneumoniae induced rash and mucositis," "Mycoplasma pneumoniae rash and mucositis," "Mycoplasma pneumoniae rash," "Mycoplasma pneumoniae mucositis," "MIRM," "Mycoplasma induced rash and mucositis," "Mycoplasma rash and mucositis," "Mycoplasma rash," and "Mycoplasma mucositis." Data was extracted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

One hundred and seventy-five records were initially screened, and nineteen studies were included in the review, leading to a total of 27 patients. Patients had a mean age of 16 years old (Range 4 - 46 years old), with the majority being males (74%). Pulmonary symptoms tended to precede extrapulmonary symptoms on an average of 7.8 days. Extrapulmonary symptoms consisted of oral lesions (96.3%) followed by ocular lesions (92.6%) and genital lesions (59.3%). Female patients were more likely to have genital lesions (71.4%) when compared with male patients (55%). Cutaneous rashes occurred in approximately one-half of the patients, which supports the theory that MIRM is a separate clinical entity from SJS and other related skin disorders.Confirmatory testing for MIRM was performed using IgM/IgG Mycoplasma antibody testing or PCR in 19 (66.7%) and 6 (22.2%) patients respectively, although four cases reported the use of both serology and PCR, while five did not report confirmatory testing. Systemic antibiotics were used frequently in treatment 22 patients (77.8%) and 27 (100%) of the patients received various supportive care. Approximately 11 (37%) patients of reported cases used systemic steroids to reduce systemic inflammation. Other systemic treatments were used in six (21.4%) cases, and included intravenous immunoglobulins and cyclosporine A. Only eight patients (22.2%) reported having any lasting sequelae.

CONCLUSION

Mycoplasma-induced rash and mucositis is a recently described extra-pulmonary manifestation of Mycoplasma pneumoniae infections. To the best of the authors' knowledge, this is the first systematic review of the MIRM literature since the introduction of the diagnosis in 2014. The authors hope that this review can serve to better our current understanding and lead to improved identification, work-up, and treatment of this disease. One notable limitation of this study is the relatively small sample size, which is due to the recent introduction of the term.

Childhood epidermal necrolysis and erythema multiforme major: a multicentre French cohort study of 62 patients

INTRODUCTION

The distinction between epidermal necrolysis [EN; including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN) and overlap syndrome] and erythema multiforme major (EMM) in children is confusing. We aimed to better describe and compare these entities.

MATERIALS AND METHODS

This French retrospective multicentre study included children ≤18 years old referred for EN or EMM between 1 January 2008 and 1 March 2019. According to pictures, children were reclassified into TEN/overlap, SJS or EMM/unclassified (SJS/EMM) groups and compared for epidemiological and clinical data, triggers, histology and follow-up.

RESULTS

We included 62 children [43 boys, median age 10 years (range 3-18)]: 16 with TEN/overlap, 11 SJS and 35 EMM. The main aetiologies were drugs in EN and infections (especially Mycoplasma pneumoniae) in EMM (P < 0.001), but 35% of cases remained idiopathic (TEN/overlap, 47%; SJS, 24%; EMM, 34%). The typical target lesions predominated in EMM (P < 0.001), the trunk was more often affected in EN (P < 0.001), and the body surface area involved was more extensive in EN (P < 0.001). Mucosal involvement did not differ between the groups. Two patients with idiopathic TEN died. Histology of EMM and EN showed similar features. The recurrence rate was 42% with EMM, 7% with TEN/overlap and 0 with SJS (P < 0.001). Sequelae occurred in 75% of EN but involved 55% of EMM.

CONCLUSION

Clinical features of EN and EMM appeared well demarcated, with few overlapping cases. Idiopathic forms were frequent, especially for EN, meaning that a wide and thorough infectious screening, repeated if needed, is indicated for all paediatric cases of EN/EMM without any trigger drug. We propose a comprehensive panel of investigations which could be a standard work-up in such situation. Sequelae affected both EN and EMM.

Current Pharmacogenetic Perspective on Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis

Adverse drug reactions are a public health issue that draws widespread attention, especially for Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) which have high mortality and lack of efficacious treatment. Though T-cell-mediated HLA-interacted immune response has been extensively studied, our understanding of the mechanism is far from satisfactory. This review summarizes infection (virus, bacterial, and mycoplasma infection), an environmental risk factor, as a trigger for SJS/TEN. The mutations or polymorphisms of drug metabolic enzymes, transporters, receptors, the immune system genes, and T-cell-mediated apoptosis signaling pathways that contribute to SJS/TEN are discussed and summarized. Epigenetics, metabolites, and mobilization of regulatory T cells and tolerogenic myeloid precursors are emerged directions to study SJS/TEN. Ex vivo lymphocyte transformation test has been exploited to aid in identifying the causative drugs. Critical questions on the pathogenesis of SJS/TEN underlying gene polymorphisms and T cell cytotoxicity remain: why some of the patients carrying the risky genes tolerate the drug and do not develop SJS/TEN? What makes the skin and mucous membrane so special to be targeted? Do they relate to skin/mucous expression of transporters? What is the common machinery underlying different HLA-B alleles associated with SJS/TEN and common metabolites?

Role of CD123 (+) Plasmacytoid Dendritic Cells in Etiologically Different Variants of Erythema Multiforme: A Monocentric Retrospective Study

Plasmacytoid dendritic cells (pDCs) constitute a subset of dendritic cells known to be the “professional” interferon type I (IFN-I) producers. pDCs play an important role in antiviral immunity, as well as linking innate and adaptive immunity. Under normal conditions pDCs are not present in skin. They are shown to be a part of the inflammatory infiltrate in different skin conditions including erythema multiforme (EM). This condition is considered to be a cell-mediated immune reaction to a wide variety of agents, most commonly herpes simplex virus. Nevertheless, the pathophysiology of EM still remains unclear. In this study, we grouped 32 biopsies from 30 patients diagnosed with EM, based on their etiology and analyzed the density and distribution of CD123 positive pDCs. In all cases we observed a greatly increased number of pDCs in the dermal inflammatory infiltrate. Virally-induced EM (by herpes simplex virus (HSV) and other viruses) was more likely to have a significantly higher number of pDCs compared to non-virally associated EM. Hence, we think that pDCs play a key role in the pathogenesis of EM independent of etiology and may play an increased role in virally-associated cases. Further studies on pDCs would clarify their importance in EM and improve our understanding of the pathophysiology of this disease.

Mucosal Respiratory Syndrome: A Systematic Literature Review

BACKGROUND

Mycoplasma pneumoniae atypical pneumonia is frequently associated with erythema multiforme. Occasionally, a mycoplasma infection does not trigger any cutaneous but exclusively mucosal lesions. The term mucosal respiratory syndrome is employed to denote the latter condition. Available reviews do not address the possible association of mucosal respiratory syndrome with further atypical bacterial pathogens such as Chlamydophila pneumoniae, Chlamydophila psittaci, Coxiella burnetii, Francisella tularensis, or Legionella species. We therefore performed a systematic review of the literature addressing this issue in the National Library of Medicine, Excerpta Medica, and Web of Science databases.

SUMMARY

We found 63 patients (≤18 years, n = 36; >18 years, n = 27; 54 males and 9 females) affected by a mucosal respiratory syndrome. Fifty-three cases were temporally associated with a M. pneumoniae and 5 with a C. pneumoniae infection. No cases temporally associated with C. psittaci, C. burnetii, F. tularensis, or Legionella species infection were found. Two cases were temporally associated with Epstein-Barr virus or influenzavirus B, respectively.

Mycoplasma pneumoniae-induced rash and mucositis: A new entity

Mycoplasma pneumoniae is a well-known cause of community-acquired pneumonia, mostly associated with dermatological manifestations especially with mucosal involvement and targetoid cutaneous lesions. For many years, it was considered among the spectrum of erythema multiforme. Recently, some authors have recommended the creation of a new syndrome called "mycoplasma-induced rash and mucositis." This new syndrome has distinct epidemiological, clinical and histological features making it different from drug-induced Stevens-Johnson syndrome, toxic epidermal necrosis and erythema multiforme. Herein, we report two patients with acute Mycoplasma pneumoniae respiratory tract infection presenting severe mucocutaneous lesions in accordance with this new syndrome.

Clonal expansion of CD4+CD8+ T cells in an adult patient with Mycoplasma pneumoniae-associated Erythema multiforme majus

Background

Erythema multiforme (EM) is an acute, immune-mediated mucocutaneous disease, most often preceded by herpes simplex virus (HSV) infection or reactivation. Mycoplasma pneumoniae (Mp) is considered the second major trigger of EM and is often associated with an atypical and more severe presentation of disease, characterized by prominent mucosal involvement. However, contrary to HSV-associated Erythema multiforme (HAEM), immunological mechanisms of Mp-associated EM remain unclear.

Case presentation

We present the case of a 50-year-old male patient presenting with community-acquired pneumonia (CAP) and erythema multiforme majus (EMM). Acute Mp infection was diagnosed by seroconversion, with no evidence of HSV infection as a cause of EMM. We performed immune phenotyping of blister fluid (BF) and peripheral blood (PB) T cells and detected a clonally expanded TCRVβ2⁺ T cell population that was double positive for CD4 and CD8, and expressed the cytotoxic markers granulysin and perforin. This CD4⁺CD8⁺ population comprised up to 50.7% of BF T cells and 24.9% of PB T cells. Two years prior to the onset of disease, the frequency of PB CD4⁺CD8⁺T cells had been within normal range and it gradually returned to baseline levels with the resolution of symptoms, suggesting an involvement of this population in EMM disease pathophysiology.

Conclusions

This report is the first to provide a phenotypic description of lesional T cells in Mp-associated EMM. Characterizing the local immune response might help to address pathophysiological questions and warrants further systematic research.

Clinical features of recurrent Mycoplasma pneumoniae-induced rash and mucositis

BACKGROUND/OBJECTIVES

The characteristics of patients experiencing recurrent Mycoplasma pneumoniae-induced rash and mucositis (MIRM) are not well understood. We aimed to characterize patients with recurrent disease by comparing the demographics, skin and mucosal involvement, seasonality, and treatment to those with single episodes (isolated MIRM).

METHODS

This retrospective case series screened all patients seen by our dermatology inpatient consult service from September 2014 to March 2020. Cases were selected based on laboratory and clinical criteria that confirmed a diagnosis of MIRM.

RESULTS

We identified 13 patients with MIRM: 5 who experienced recurrence (38%) and 8 with isolated, single episodes without recurrence. Mean age was 13.6 years for initial episodes in the recurrent patients compared to 11.7 in patients with isolated episodes. All 5 recurrent MIRM patients were male (compared with 75% of isolated MIRM patients) and predominantly Black (60%, compared with 25%). Most episodes overall (isolated and recurrent) occurred from the months of October to February. Recurrences after initial MIRM episode had less severe skin and mucosal findings, often involving only one mucous membrane, less frequent need for hospital admission, and shorter duration of hospital stay. Prophylactic treatments and treatments beyond supportive care were of unclear value.

CONCLUSIONS

Some characteristics of MIRM differ between patients with recurrent and isolated disease. Clinicians should be aware of the potential for recurrence, which occurred in 38% of our cohort. Although recurrences after initial MIRM episode tended to be less severe, there is still potential for prolonged hospitalizations with recurrent episodes. More evidence is needed regarding effective preventive and treatment regimens in patients with recurrent MIRM.

Frequency and Clinical Presentation of Mucocutaneous Disease Due to Mycoplasma pneumoniae Infection in Children With Community-Acquired Pneumonia

Importance

The diagnosis of Mycoplasma pneumoniae infection as the cause of mucocutaneous disease is challenging because current diagnostic tests are not able to differentiate M pneumoniae infection from carriage.

Objective

To examine the frequency and clinical presentation of M pneumoniae-induced mucocutaneous disease in children with community-acquired pneumonia (CAP) using improved diagnostics.

Design, Setting, and Participants

This prospective, longitudinal cohort study included 152 children aged 3 to 18 years with CAP enrolled in a CAP study from May 1, 2016, to April 30, 2017, at the University Children's Hospital Zurich. Children were inpatients or outpatients with clinically defined CAP according to the British Thoracic Society guidelines. Data analysis was performed from July 10, 2017, to June 29, 2018.

Main Outcomes and Measures

Frequency and clinical presentation of M pneumoniae-induced mucocutaneous disease in childhood CAP. Mycoplasma pneumoniae infection was diagnosed by polymerase chain reaction (PCR) of oropharyngeal samples and confirmed with the measurement of specific peripheral blood IgM antibody-secreting cells by enzyme-linked immunospot assay to differentiate M pneumoniae-infected patients from carriers with CAP caused by other pathogens. Mucocutaneous disease was defined as any eruptive lesion that involved skin and/or mucous membranes occurring during the CAP episode.

Results

Among 152 enrolled children with CAP (median [interquartile range] age, 5.7 [4.3-8.9] years; 84 [55.3%] male), 44 (28.9%) tested positive for M pneumoniae by PCR; of these, 10 children (22.7%) developed mucocutaneous lesions. All 10 patients with mucocutaneous eruptions tested positive for specific IgM antibody-secreting cells. Skin manifestations were found in 3 cases (2.8%) of M pneumoniae PCR-negative CAP (P < .001). The spectrum of M pneumoniae-induced mucocutaneous disease included M pneumoniae-induced rash and mucositis (3 cases [6.8%]), urticaria (2 cases [4.5%]), and maculopapular skin eruptions (5 cases [11.4%]). Two patients had ocular involvement as the sole mucosal manifestation (bilateral anterior uveitis and nonpurulent conjunctivitis). Patients with M pneumoniae-induced mucocutaneous disease had longer duration of prodromal fever (median [interquartile range], 10.5 [8.3-11.8] vs 7.0 [5.5-9.5] days; P = .02) and higher C-reactive protein levels (median [interquartile range], 31 [22-59] vs 16 [7-23] mg/L; P = .04) than patients with CAP due to M pneumoniae without mucocutaneous manifestations. They were also more likely to require oxygen (5 [50%] vs 1 [5%]; P = .007), to require hospitalization (7 [70%] vs 4 [19%]; P = .01), and to develop long-term sequelae (3 [30%] vs 0; P = .03).

Conclusions and Relevance

Mucocutaneous disease occurred significantly more frequently in children with CAP due to M pneumoniae than in children with CAP of other origins. Mycoplasma pneumoniae-induced mucocutaneous disease was associated with increased systemic inflammation, morbidity, and a higher risk of long-term sequelae.

Mycoplasma pneumoniae-Induced Rash and Mucositis in a Previously Healthy Man: A Case Report and Brief Review of the Literature

We describe a case of a 33-year-old-male with Mycoplasma pneumoniae-induced rash and mucositis and review the literature on this newly described syndrome.

Mycoplasma Pneumoniae Induced Rash and Mucositis with Bilateral Otitis Media and Sinusitis

Mycoplasma pneumoniae induced rash and mucositis (MIRM) is a recently identified clinical entity, which describes a subset of extrapulmonary manifestations resulting from Mycoplasma pneumonia infection. Patients present with a wide variety of symptoms including cough, dyspnea, mucositis, conjunctivitis, with or without a variable cutaneous rash. A 24-year-old male presented to the emergency department with worsening dyspnea and new-onset oral, ocular, and genital mucosal lesions. The patient was also found to have bilateral otitis media with tympanic membrane rupture and ethmoid sinusitis upon further evaluation. The patient was originally diagnosed with atypical pneumonia leading to acute hypoxic respiratory failure and was admitted to inpatient care. Work-up revealed positive Mycoplasma pneumoniae immunoglobulin M, and the patient was subsequently diagnosed with MIRM. The patient was provided with supportive care as well as systemic antibiotics, and he fully recovered by day 12 without complication. No standardized treatment guidelines exist for MIRM, and it is universally accepted that supportive management is the mainstay of treatment, consisting of pain management, intravenous hydration, and mucosal care. Although the majority of MIRM patients are generally known to have a full recovery (81%), a variety of ocular, oral, and genital complications have been noted in the literature. Here we present a unique case of MIRM in a 24-year-old male who also had ethmoid sinusitis and bilateral otitis media with unilateral tympanic membrane perforation - two head and neck symptoms not described in previous literature.

Uncommon erythema multiforme in small children: experience of a single Romanian pediatric unit: Two case reports

RATIONALE

Erythema multiforme (EM) is an immune-mediated disease with mucocutaneous localization and plurietiologic determinism. The term "multiforme" refers to the variety of aspects that the lesions can take from patient to patient and during evolution in a single patient.

PATIENT CONCERNS

We have selected 2 cases of small children diagnosed with different etiology of EM to illustrate the importance of a correct and fast diagnosis. Case 1 involves a 2-year-old girl from a rural area who presented with fever and pruritic erythematous papular eruption. The onset of the symptoms was 3 days before presentation with fever and ulcerative lesions on the oral and labial mucosa, followed by the appearance of erythematous macular lesions, with progressive confluence to intense pruritic patches. The 2nd involves a 2-year-old boy with fever, loss of appetite, productive cough, and petechiae. He had corticosensible immune thrombocytopenia from the age of 6 months, with many recurrences. The patient received treatment with ampicillin/sulbactam and symptomatics for an erythemato-pultaceous angina. During the 2nd day of treatment the patient developed an erythematous macular eruption on the face, scalp, trunk, and limbs, with bullae formation.

DIAGNOSES

The 1st patient was diagnosed based on biologic findings: positive inflammatory syndrome, elevated level of anti-Mycoplasma pneumoniae immunoglobulin M antibodies and immunoglobulin E. Histopathologic examination described papillary dermal edema, inflammatory infiltrate, and lymphocyte exocytosis. In the 2nd case, the hemoleucogram identified 12,000/mm platelets and the medulogram aspect was normal. Serology for Epstein-Barr virus was negative. The diagnosis was EM secondary to M pneumoniae infection in case 1 and secondary to administration of ampicillin/sulbactam in case 2.

INTERVENTIONS

In both cases, etiopathogenic treatment consisting of steroidal antiinflammatory drugs, antihistamines was administered. Because of specific etiology, the 1st case received antibiotics.

OUTCOMES

The evolution was favorable in 10 to 14 days; the patients were discharged after etiopathogenic treatment consisting of steroidal antiinflammatory drugs, antihistamines, and/or antibiotics.

LESSONS

Performing a detailed clinical examination, medical history of drug use, infection or general diseases can establish a good diagnosis of EM. Histopathologic examination can help. The treatment is etiologic, pathogenic, and symptomatic. EM usually has a self-limited evolution.

[What's new in clinical dermatology?]

In this article, we performed a review of all new data of clinical relevance for the dermatologists that were published in the medical literature between September, 2017 and September, 2018. Besides advances that will be useful in day-to-day dermatological practice, we intended to give a more general perspective to this review by taking into account certain international health issues that might in final concern each of us in a globalized world. Focus were more particularly done on the following topics: infectious diseases (including sexually transmitted infections), neglected tropical diseases, adverse effects of drugs, bullous diseases, allergology, wound healing, dermatology on black skin, and public health dermatology.

Interventions for erythema multiforme: a systematic review

Treatment of erythema multiforme (EM) is not codified. We performed a systematic review of the effect of any topical or systemic treatment on time to healing and frequency of episodes with acute and chronic forms of EM in adults. Four databases (MEDLINE, CENTRAL, EMBASE and LILACS) and other sources were searched for articles published up to 20 March 2018. Randomized control trials (RCTs), observational studies and case series (n ≥ 10) were considered. From 1558 references, we included one RCT and six case series. The RCT (n = 20) showed a significant difference in complete remission of EM with continuous acyclovir vs. placebo over 6 months. One case series found a mean reduction in flare duration with thalidomide for recurrent EM (5.1 vs. 16.2 days; n = 20). Adverse events were poorly or not reported in included studies. Quality of life was never assessed. One limitation of our study is that we excluded the cases of isolated mucosal EM in order to prevent inclusion of Stevens-Johnson syndrome cases. In conclusion, there is low-level evidence for continuous acyclovir treatment for recurrent EM (one RCT). Evidence for other treatments is only based on retrospective case series. Results for thalidomide, in particular, encourage further research. Data concerning safety are insufficient. PROSPERO registration no. CRD42016053175.