A critical reappraisal of the current data on drug-induced linear immunoglobulin A bullous dermatosis: A real and separate nosological entity?

Linear IgA bullous dermatosis secondary to drugs: a real-world pharmacovigilance study of the FDA adverse event reporting system

Background

Linear IgA bullous dermatosis (LABD) is a rare autoimmune blistering disease. The induction of LABD by medications is a critical issue, with previous studies highlighting the link between specific drugs and the onset of LABD. This study aims to assess the reported associations between LABD and numerous available medications using the FDA adverse event reporting system (FAERS).

Methods

The study encompassed FAERS reports spanning the years 2004-2024. Medical Dictionary for Regulatory Activities (MedDRA) was used to identify cases of LABD. The Reporting Odds Ratio, Proportional Reporting Ratio, Bayesian Confidence Propagation Neural Network, and Empirical Bayes Geometric Mean were calculated to assess the reported associations between available drugs and LABD. A significant statistical association was considered when a drug signal met the criteria of all four algorithms.

Results

In the FAERS database analysis, we identified 1,394 adverse event (AE) reports associated with LABD. The gender distribution of reports was relatively balanced, with the highest proportion in the 66-85 age group. The United States had the highest number of reports. Vancomycin and Amoxicillin were the most frequently reported drugs, with 559 and 58 reports, respectively. Through disproportionality analysis, we identified 34 drugs significantly associated with AEs of LABD, including antibiotics, antifungal medications, analgesics, nonsteroidal anti-inflammatory drugs, cardiovascular medications, and calcium channel blockers, among which the antibiotic Vancomycin showed the highest association. These results emphasize the need for further clinical attention to the safety of specific medications.

Conclusion

This is the first real-world study using the FAERS database to investigate drug-induced LABD. LABD is closely associated with antibiotic medications. Close monitoring of patients is required when these medications are used clinically to promptly detect and manage potential AEs such as LABD.

Examining the effect of direct-from-blood bacterial testing on antibiotic administration and clinical outcomes: a protocol and statistical analysis plan for a pragmatic randomised trial

INTRODUCTION

Patients with suspected bacterial infection frequently receive empiric, broad-spectrum antibiotics prior to pathogen identification due to the time required for bacteria to grow in culture. Direct-from-blood diagnostics identifying the presence or absence of bacteria and/or resistance genes from whole blood samples within hours of collection could enable earlier antibiotic optimisation for patients suspected to have bacterial infections. However, few randomised trials have evaluated the effect of using direct-from-blood bacterial testing on antibiotic administration and clinical outcomes. This manuscript describes the protocol and statistical analysis plan for a randomised trial designed to evaluate the effect of blood cultures plus direct-from-blood bacterial testing results compared with blood culture results alone on antibiotic administration and clinical outcomes.

METHODS AND ANALYSIS

We are conducting a prospective, single-centre, parallel-group, non-blinded, pragmatic, randomised trial. The trial will enrol 500 adult patients presenting to the emergency department at Vanderbilt University Medical Center with suspected bacterial infection who have been initiated on empiric intravenous vancomycin. Eligible patients are randomised 1:1 to receive Food and Drug Administration-approved direct-from-blood bacterial testing in addition to blood cultures or blood cultures alone. The primary outcome is the time to the last dose of intravenous vancomycin within 14 days of randomisation. The secondary outcome is the time to the last dose of systemic antipseudomonal beta-lactam antibiotics within 14 days of randomisation. Additional outcomes include highest stage of acute kidney injury, lowest platelet count and receipt of kidney replacement therapy within 14 days of randomisation, as well as hospital-free days, intensive care unit-free-days and all-cause, in-hospital mortality within 28 days of randomisation. Enrolment began on 13 December 2023.

ETHICS AND DISSEMINATION

The trial involves human participants and was approved by the Vanderbilt University Medical Center institutional review board with a waiver of informed consent (IRB#231229). Results will be submitted in a peer-reviewed journal and presented at scientific conferences.

TRIAL REGISTRATION NUMBER

NCT06069206.

Swab Testing to Optimize Pneumonia treatment with empiric Vancomycin (STOP-Vanc): study protocol for a randomized controlled trial

BACKGROUND

Vancomycin, an antibiotic with activity against methicillin-resistant Staphylococcus aureus (MRSA), is frequently included in empiric treatment for community-acquired pneumonia (CAP) despite the fact that MRSA is rarely implicated in CAP. Conducting polymerase chain reaction (PCR) testing on nasal swabs to identify the presence of MRSA colonization has been proposed as an antimicrobial stewardship intervention to reduce the use of vancomycin. Observational studies have shown reductions in vancomycin use after implementation of MRSA colonization testing, and this approach has been adopted by CAP guidelines. However, the ability of this intervention to safely reduce vancomycin use has yet to be tested in a randomized controlled trial.

METHODS

STOP-Vanc is a pragmatic, prospective, single center, non-blinded randomized trial. The objective of this study is to test whether the use of MRSA PCR testing can safely reduce inappropriate vancomycin use in an intensive care setting. Adult patients with suspicion for CAP who are receiving vancomycin and admitted to the Medical Intensive Care Unit at Vanderbilt University Medical Center will be screened for eligibility. Eligible patients will be enrolled and randomized in a 1:1 ratio to either receive MRSA nasal swab PCR testing in addition to usual care (intervention group), or usual care alone (control group). PCR testing results will be transmitted through the electronic health record to the treating clinicians. Primary providers of intervention group patients with negative swab results will also receive a page providing clinical guidance recommending discontinuation of vancomycin. The primary outcome will be vancomycin-free hours alive, defined as the expected number of hours alive and free of the use of vancomycin within the first 7 days following trial enrollment estimated using a proportional odds ratio model. Secondary outcomes include 30-day all-cause mortality and time alive off vancomycin.

DISCUSSION

STOP-Vanc will provide the first randomized controlled trial data regarding the use of MRSA nasal swab PCR testing to guide antibiotic de-escalation. This study will provide important information regarding the effect of MRSA PCR testing and antimicrobial stewardship guidance on clinical outcomes in an intensive care unit setting.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06272994. Registered on February 22, 2024.

Linear IgA Bullous Dermatosis in Korea Using the Nationwide Health Insurance Database

(1) Background: Linear immunoglobulin A bullous dermatosis (LABD) is a rare autoimmune, subepidermal blistering disease, characterized by linear IgA deposits along the epidermal basement membrane. LABD is idiopathic and is associated with medication and systemic autoimmune diseases. (2) Methods: We investigated the demographic characteristics, disease course, causative agents, and associated diseases in Korean patients with LABD. The Korean Health Insurance Review and Assessment Service database was used to obtain data. We identified 670 LABD cases between 2010 and 2022. (3) Results: The annual incidence of LABD was 1.3 per 100,000 persons, with a higher prevalence in individuals ≥60 years old. The patients were treated with dapsone for 30.7 ± 56.7 days, had 1.3 ± 0.7 hospital visits, and were hospitalized for 19.8 ± 19.7 days. Risk factors, including malignancy, commonly preceded LABD. Antibiotic use, specifically vancomycin and third-generation cephalosporins, was a risk factor. The mean age of LABD diagnosis was 55.9 ± 21.7 years. (4) Conclusion: This is the first published study to assess a nationwide cohort for LABD. The incidence of LABD was higher than that in other studies. Most case reports have linked LABD with the administration of specific antibiotics; however, this study shows there were more associations with other conditions.

Drug-Induced Linear IgA Bullous Dermatosis in an Oncologic Patient

Blister formation in the skin can result from various conditions, such as autoimmune disorders, drug reactions, infections, etc. A comprehensive patient assessment may offer clues for diagnosis. Linear IgA bullous dermatosis (LABD) is a rare subepidermal blistering disorder characterized by the deposition of IgA at the basement membrane zone of the skin and mucous membranes. Here, we describe a case of a patient with a new onset of painless blisters located in the skin and oral mucosa after initiating antibiotic treatment.

Eosinophil-rich linear IgA bullous dermatosis induced by mRNA COVID-19 booster vaccine

We present a case of eosinophil-rich linear IgA bullous disease (LABD) following the administration of a messenger RNA COVID-19 booster vaccine. A 66-year-old man presented to the emergency department with a 3-week history of a pruritic blistering rash characterized by fluid-filled bullae and multiple annular and polycyclic plaques. He was initially diagnosed with bullous pemphigoid based on a biopsy showing a subepidermal blister with numerous eosinophils. However, direct immunofluorescence studies showed linear IgA and IgM deposition along the basement membrane zone with no immunoreactivity for C3 or IgG. Additionally, indirect immunofluorescence was positive for IgA basement membrane zone antibody. The patient was subsequently diagnosed with LABD and initiated on dapsone therapy with resolution of his lesions at 3-month follow-up. This case illustrates the growing number of autoimmune blistering adverse cutaneous reactions from vaccination. Dermatopathologists should be aware that features of autoimmune blistering diseases can overlap and may not be distinguishable based on these histopathological findings alone. Confirmation with direct immunofluorescence and/or serological studies may be necessary for accurate diagnosis.

Linear Immunoglobulin a Bullous Dermatosis in Children

Linear Immunoglobulin A Bullous Disease (LABD) is a rare dermatosis whose pathomechanisms are not yet completely understood. LABD has different features characterizing adults and children in terms of potential triggers, clinical manifestations, and prognosis. The aim of the present study is to review all neonatal and pediatric cases of LABD and summarize the major characteristics. Childhood LABD is mainly idiopathic with a benign prognosis. Neonatal cases are difficult to differentiate from infectious diseases and usually have a poor prognosis. Drugs are one of the possible triggers that can activate autoimmune responses through antigen mimicry and epitope spreading as well as different stimuli (e.g., infections, inflammatory diseases, trauma). The gold standard for the diagnosis is based on direct immunofluorescence. Prognosis is generally favorable but often depends on the prompt dermatological diagnosis, treatment and follow-up guaranteed by a multidisciplinary team, including pediatricians for this group of age.

Olanzapine-Related Somnambulism: A Systematic Review of Literature and a Case Report of Anorexia Nervosa

BACKGROUND

Somnambulism, or sleepwalking (SW), is one of the most common forms of arousal parasomnias. It is characterized by different complex motor behaviors leading to unwanted movements in bed or walking during sleep. It can be the consequence of psychological stress, abnormal breathing during sleep, high fever, or drug adverse effects. There is evidence of an association between antipsychotic treatment, including olanzapine, and SW.

METHODS

We present the case of a patient experiencing treatment-resistant anorexia nervosa whose somnambulism re-exacerbated after the addition of a low dose of olanzapine, following the CARE (CAse REport) Statement and Checklist. We also conducted a systematic review of the literature on olanzapine-induced somnambulism following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, PsychINFO, and the Cochrane Library databases were independently reviewed up to January 2021 for articles reporting olanzapine-related somnambulism cases, without language or time restriction.

RESULTS

We describe a case of somnambulism in a patient initially admitted to our hospital for anorexia nervosa and treated with a low dose of olanzapine. This is the first case of SW induced by olanzapine in eating disorders to be reported. Up-to-date olanzapine-related somnambulism was described in 8 patients experiencing psychiatric disorders (ie, schizophrenia and bipolar disorder).

CONCLUSIONS

To provide a reliable estimate of incidence and prevalence for olanzapine-related somnambulism, large-scale, pharmacovigilance studies are required, to allow for comparisons of overall clinical characteristics, outcomes, including time to recovery, between different treatment options. Clinician awareness should be enhanced, and attention should be given to such infrequent adverse effects associated with antipsychotics.

Unravelling cases of clozapine-related Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) in patients reported otherwise: A systematic review

BACKGROUND

The drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a drug-induced hypersensitivity reaction.

AIMS

Aim was to review reports of clozapine-related reactions fulfilling the registry of severe cutaneous adverse reaction (RegiSCAR) criteria for DRESS syndrome reported as such or otherwise, to provide a descriptive overview of demographic patterns, clinical manifestations, and DRESS course and investigate associations between demographic, DRESS parameters, and clinical outcomes.

METHODS

This review was conducted following preferred reporting items for systematic reviews and meta-analyses guidelines and registered with PROSPERO (registration number CRD42020156385). We searched PubMed/Embase/PsychInfo/Cochrane for reports of clozapine-related reactions meeting RegiSCAR criteria. Associations between RegiSCAR scores and time-to-recovery with demographic/clinical variables were assessed. Demographic/clinical characteristics of patients with versus without reported DRESS were compared using non-parametrical tests.

RESULTS

We identified 26 reports of 27 patients meeting RegiSCAR criteria. Males (n = 19, 70.4%) and patients with schizophrenia (n = 18, 66.7%) were mainly affected. Twelve patients (44.4%) received clozapine-monotherapy. DRESS symptoms manifested within a month after clozapine initiation (n = 24, 88.9%). Lungs and liver were the most common organs involved (n = 12, 44.4%; n = 11, 40.7%), with a mean time to recovery of 33.75 days. Clozapine rechallenge led to DRESS recurrence in four patients. Death rate was 7.4%. No associations were detected between RegiSCAR criteria or days to recovery with any demographic/clinical variables. No differences between patients with versus without reported DRESS were detected.

CONCLUSIONS

Clozapine-related DRESS may be rare, but also underreported. Clinicians need to be aware of it even in patients under clozapine-monotherapy or without skin rash.

Linear IgA Bullous Dermatosis Preceding the Diagnosis of Primary Sclerosing Cholangitis and Ulcerative Colitis: A Case Report

Linear IgA bullous dermatosis (LABD) is a rare autoimmune blistering disorder seen in the pediatric and adult populations that is often linked to a medication, infection, or underlying gastrointestinal, hepatobiliary, or autoimmune disease. In this study, we describe the case of a 23-year-old white man whose presentation and diagnosis of LABD ultimately led to the discovery of underlying primary sclerosing cholangitis (PSC) and ulcerative colitis (UC). His dermatitis resolved with topical steroids and dapsone, and he is undergoing systemic treatment for his UC and PSC. This exceptional case further validates the association between LABD with UC, strengthens that with PSC, and underscores the importance of alerting clinicians to consider conducting a systemic workup in addition to thorough medication history on making the diagnosis of LABD.

An array of unusual clinical features in a woman with amlodipine-induced linear immunoglobulin A disease

Linear immunoglobulin A disease (LAD) is a rare, autoimmune, vesicular-bullous disease that is either idiopathic or drug-induced, most commonly by vancomycin and in rare instances by amlodipine. In drug-induced LAD, certain uncommon and atypical clinical features can occur. In our patient, a 49-year-old woman with amlodipine-induced LAD, atypical features such as koebnerization and palmo-plantar involvement occurred. She presented with tense, clear fluid-filled vesicles, bullae, and erosions all over her body, especially on the palms and soles, with some lesions showing a string-of-pearls appearance. The lesions were preceded by pruritus, and the patient had changed her anti-hypertensive medication from telmisartan to telmisartan-amlodipine for previous 10 days. Skin biopsy and direct immunofluorescence testing confirmed LAD. During the hospital stay, along with new crops of lesions, a few vesicles were present along the lines where she had scratched and the band of tight elastic sleeves of the sterile gown she wore, which is suggestive of koebnerization. Knowing the atypical manifestations of drug-induced LAD may aid clinicians in determining an early diagnosis, and LAD should be an important consideration in the differential diagnosis of vesiculobullous disease with palmar-plantar involvement. Amlodipine is a commonly used anti-hypertensive drug, so knowledge of its potential to cause this disease is important. Furthermore, knowing the potential for koebnerization, avoidance of trauma and the gentle handling of these patients can lead to early recovery from this self-limiting disease.

Linear IgA bullous dermatosis in adults and children: a clinical and immunopathological study of 38 patients

BACKGROUND

Linear IgA bullous dermatosis (LABD) is a rare autoimmune subepithelial vesiculobullous disease due to IgA autoantibodies directed against different antigens of the basement membrane zone (BMZ) of the skin and/or mucosae. It affects mainly preschool-aged children and adults, with only few studies on large series. The aim of this study was to assess possible differences between adults and children regarding clinical presentation, immunopathologic features, management and course of the disease.

METHODS

A retrospective review of 38 LABD patients, followed-up from November 2006 to September 2018, was performed.

RESULTS

Of 38 patients, 27 were adults and 11 children. Mean age at diagnosis was 5.4 years and 60.6 years in the pediatric and adult group, respectively. Considering both groups, limbs were the most commonly involved site (73.7%), followed by trunk (55.3%), head (36.8%) and buttocks (13.2%). Interestingly, head (p = 0.008), particularly perioral (p = 0.001), involvement, as well as "string of pearls" arrangement (p = 0.03), were more prevalent in children. Mucosal involvement was seen in 9 (23.7%) patients and was more frequent in children than adults (45.5% vs 14.8%, respectively, p = 0.09). Linear IgA deposits along the BMZ were observed in 30 patients (78.9%), while linear/granular IgA deposits in 8 patients (21.1%). Dapsone was the most commonly used drug (78.9%) and complete remission was achieved in most cases (81.6%).

CONCLUSIONS

Our epidemiological and clinicopathological findings relative to a large cohort of LABD patients are mostly consistent with the literature data. Interestingly, head, notably perioral, involvement and "string of pearls" arrangement occurred more frequently in the paediatric than adult group. The above clinical parameters may be regarded as diagnostic tools for LABD in children.

Cephalosporin-induced linear IgA dermatosis in a child: Case report and literature review

Linear IgA dermatosis (LAD) is a rare, subepidermal blistering disease with mucocutaneous involvement. It may be idiopathic or drug induced. We describe a 4-year-old girl who presented with a vesiculobullous eruption after she had been treated with cefixime for urinary tract infection. A diagnosis of drug-induced LAD was made based on clinical, histopathological, and immunofluorescence findings. Naranjo adverse drug reaction algorithm was used to assess imputability resulting with a "probable" association. In literature, cephalosporin antibiotics are rarely reported in association with LAD. To our knowledge, this is the first case of a cefixime-induced LAD among adults and children.

Drug-induced linear immunoglobulin A bullous dermatosis: A French retrospective pharmacovigilance study of 69 cases

AIMS

Linear immunoglobin A (IgA) bullous dermatosis is a rare autoimmune dermatosis considered spontaneous or drug-induced (DILAD). We assessed all DILAD cases, determined the imputability score of drugs and highlighted suspected drugs.

METHODS

Data for patients with DILAD were collected retrospectively from the French Pharmacovigilance network (from 1985 to 2017) and from physicians involved in the Bullous Diseases French Study Group and the French Investigators for Skin Adverse Reactions to Drugs. Drug causality was systematically determined by the French imputability method.

RESULTS

Of the 69 patients, 42% had mucous membrane involvement, 20% lesions mimicking toxic epidermal necrolysis (TEN), 21% eosinophil infiltrates and 10% keratinocytes necrosis. Direct immunofluorescence, in 80%, showed isolated linear IgA deposits. Vancomycin (VCM) was suspected in 39 cases (57%), 11 had TEN-like lesions, as compared with three without VCM suspected. Among the 33 patients with a single suspected drug, 85% had an intrinsic imputability score of I4. Among them, enoxaparin, minocycline and vibramycin were previously unpublished. For all patients, the suspect drug was withdrawn; 15 did not receive any treatment. First-line therapy for 31 patients was topical steroids. Among the 60 patients with available follow-up, 52 achieved remission, 10 without treatment. Four patients experienced relapse, four died and five had positive accidental rechallenges.

CONCLUSIONS

There is no major clinical difference between DILAD and idiopathic linear IgA bullous dermatosis, but the former features a higher prevalence of patients mimicking TEN. VCM, suspected in more than half of the cases, might be responsible for more severe clinical presentations. We report three new putative drugs.

Linear IgA bullous dermatosis

Aim: to present a clinical case of linear IgA bullous dermatosis.Materials and methods. A 44 years old patient complaining of skin rashes on the trunk and extremities, accompanied by severe itching was examined. We carried out a morphological investigation of biopsy samples derived from the lesion and apparently unaffected skin areas using the method of indirect immunofluorescence.Results. The patient having rashes in the form of multiple vesicles and small bubbles with a tight cover, which had been grouped into figures resembling pearl necklaces, demonstrated the presence of focal subepidermal cracks (subepidermal bubble in one location), as well as a linear deposition of IgA along the epidermal basement membrane. According to the clinical picture and following the histological and immunofluorescent investigation of skin biopsies, the patient was diagnosed with linear IgA bullous dermatosis. Lesion regression was achieved as a result of systemic therapy with prednisolone at a dose of 50 mg per day.Conclusion. The diagnosis of linear IgA bullous dermatosis should be made on the basis of skin biopsy investigation by the method of indirect immunofluorescence. Systemic glucocorticosteroids are seen as an effective approach to the treatment of such patients.

Cutaneous Drug Reactions in the Elderly

Cutaneous adverse drug reactions comprise a significant proportion of all adverse drug reactions. They may mimic other dermatologic or systemic illnesses and may cause significant morbidity or mortality. Seven morphologic groups encompass the most commonly encountered cutaneous drug reaction syndromes: exanthematous (maculopapular), dermatitic/eczematous, urticarial, pustular, blistering, purpuric, and erythrodermic. Drug reactions may have significant downstream consequences for the older individual.

Vancomycin Mediates IgA Autoreactivity in Drug-Induced Linear IgA Bullous Dermatosis

Vancomycin (VCM) is known to induce linear IgA bullous dermatosis (LAD). However, in contrast to conventional LAD, in which circulating IgA autoantibodies against basement membrane proteins are commonly detected, patient sera from VCM-induced LAD yields negative results in indirect immunofluorescence microscopy, and the targeted autoantigen remains undetermined. By using sera from a typical patient with VCM-induced LAD, we identified that co-incubation of sera with VCM resulted in linear IgA deposition at the basement membrane zone by indirect immunofluorescence. Patient sera reacted with the dermal side of 1 mol/L NaCl-split skin and with the recombinant noncollagenous (i.e., NC1) domain of type VII collagen by both immunoblot and ELISA in the presence of VCM. The investigation of an additional 13 patients with VCM-induced LAD showed that 10 out of the 14 sera (71.4%) reacted with the NC1 domain of type VII collagen by ELISA when spiked with VCM, whereas only 4 (28.6%) tested positive without it. The enhancement of reactivity to NC1 by VCM, as determined by optical density via ELISA, was observed in 10 out of the 14 sera (71.4%). These findings indicate that type VII collagen is a target autoantigen in VCM-induced LAD and that VCM mediates IgA autoreactivity against type VII collagen, providing an insight into mechanisms involved in drug-induced autoimmune disease.

Vancomycin-associated linear IgA disease mimicking toxic epidermal necrolysis

Linear IgA dermatosis is a rare subepidermal autoimmune blistering disease characterized by linear deposition of IgA along the basement membrane zone. In the last three decades, many different drugs have been associated with the drug-induced form of the disease, especially vancomycin. We report a case of vancomycin-induced linear IgA disease mimicking toxic epidermal necrolysis. The aim of this work is to emphasize the need to include this differential diagnosis in cases of epidermal detachment and to review the literature on the subject and this specific clinical presentation.

Practice Gaps: Drug Reactions

The term "drug reactions" is relevant to dermatology in three categories of reactions: cutaneous drug reactions without systemic features, cutaneous drug reactions with systemic features, and systemic drugs prescribed by the dermatologist with systematic adverse effects. This article uses examples from each of these categories to illustrate several important principles central to drug reaction diagnosis and management. The information presented will help clinicians attain the highest possible level of certainty before making clinical decisions.

Bullous diseases: Kids are not just little people

Bullous diseases may be rare; however, this does not preclude the clinician from being familiar with their manifestations and treatment. After ruling out infection, genetically inherited blistering diseases are more likely to be the cause of blistering or erosions in the neonatal period, whereas immunobullous diseases are more common in adults. Published literature on immunobullous disorders reflects information gleaned from case reports and open-label case series; prospective studies and evidence-based treatments are limited. Although there may be overlapping clinical features, significant clinical differences exist between adults and children. Evidence-based treatment guidelines are limited, and information from the adult literature cannot be readily generalized to the pediatric population. This paper reviews the approach to blistering conditions and the differences among bullous pemphigoid, linear immunoglobulin A disease, dermatitis herpetiformis, pemphigus foliaceus, pemphigus vulgaris, and paraneoplastic pemphigus in adult versus pediatric patients.

Blistering disease: insight from the hemidesmosome and other components of the dermal-epidermal junction

The hemidesmosome is a specialized transmembrane complex that mediates the binding of epithelial cells to the underlying basement membrane. In the skin, this multiprotein structure can be regarded as the chief adhesion unit at the site of the dermal-epidermal junction. Focal adhesions are additional specialized attachment structures located between hemidesmosomes. The integrity of the skin relies on well-assembled and functional hemidesmosomes and focal adhesions (also known as integrin adhesomes). However, if these adhesion structures are impaired, e.g., as a result of circulating autoantibodies or inherited genetic mutations, the mechanical strength of the skin is compromised, leading to blistering and/or tissue inflammation. A particular clinical presentation emerges subject to the molecule that is targeted. None of these junctional complexes are simply compounds of adhesion molecules; they also play a significant role in signalling pathways involved in the differentiation and migration of epithelial cells such as during wound healing and in tumour invasion. We summarize current knowledge about hereditary and acquired blistering diseases emerging from pathologies of the hemidesmosome and its neighbouring proteins as components of the dermal-epidermal junction.

A gene network bioinformatics analysis for pemphigoid autoimmune blistering diseases

OBJECTIVE

In this theoretical study, a text mining search and clustering analysis of data related to genes potentially involved in human pemphigoid autoimmune blistering diseases (PAIBD) was performed using web tools to create a gene/protein interaction network.

METHODS

The Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database was employed to identify a final set of PAIBD-involved genes and to calculate the overall significant interactions among genes: for each gene, the weighted number of links, or WNL, was registered and a clustering procedure was performed using the WNL analysis. Genes were ranked in class (leader, B, C, D and so on, up to orphans). An ontological analysis was performed for the set of 'leader' genes.

RESULTS

Using the above-mentioned data network, 115 genes represented the final set; leader genes numbered 7 (intercellular adhesion molecule 1 (ICAM-1), interferon gamma (IFNG), interleukin (IL)-2, IL-4, IL-6, IL-8 and tumour necrosis factor (TNF)), class B genes were 13, whereas the orphans were 24. The ontological analysis attested that the molecular action was focused on extracellular space and cell surface, whereas the activation and regulation of the immunity system was widely involved.

CONCLUSIONS

Despite the limited knowledge of the present pathologic phenomenon, attested by the presence of 24 genes revealing no protein-protein direct or indirect interactions, the network showed significant pathways gathered in several subgroups: cellular components, molecular functions, biological processes and the pathologic phenomenon obtained from the Kyoto Encyclopaedia of Genes and Genomes (KEGG) database.

CLINICAL RELEVANCE

The molecular basis for PAIBD was summarised and expanded, which will perhaps give researchers promising directions for the identification of new therapeutic targets.

Linear IgA bullous dermatosis: comparison between the drug-induced and spontaneous forms

BACKGROUND

Linear IgA bullous dermatosis (LABD) is a rare autoimmune blistering skin disorder characterized by linear deposits of IgA along the dermoepidermal junction, visualized by direct immunofluorescence (DIF). It is usually spontaneous and drug induced.

OBJECTIVES

To compare the clinical and histological forms of LABD.

METHODS

This retrospective single-centre cohort study concerned 28 patients diagnosed with LABD between 1 January 1995 and 31 December 2010. Imputability, determined according to the French imputability method (modified Bégaud score) and Naranjo score, enabled classification into drug-induced and spontaneous LABD groups. Clinical and histological features were compared by blinded analysis of images and histological patterns.

RESULTS

Sixteen patients had spontaneous LABD and 12 had drug-induced LABD. Nikolsky sign and large erosions were significantly more frequent in drug-induced than spontaneous LABD (P = 0.003 and P = 0.03, respectively), with no between-group differences for erythematous plaques, target or target-like lesions, string of pearls, location, mucosal involvement or histological features.

CONCLUSIONS

Drug-induced LABD was more severe than the spontaneous form, with lesions mimicking toxic epidermal necrolysis. Because LABD may be polymorphic and sometimes life threatening, DIF assay is recommended for all patients with Nikolsky sign and large erosions.

Molecular diagnosis in autoimmune skin blistering conditions

Blister formation in skin and mucous membranes results from a loss of cell-cell or cell-matrix adhesion and is a common outcome of pathological events in a variety of conditions, including autoimmune and genetic diseases, viral and bacterial infections, or injury by physical and chemical factors. Autoantibodies against structural components maintaining cell-cell and cell-matrix adhesion induce tissue damage in autoimmune blistering diseases. Detection of these autoantibodies either tissue-bound or circulating in serum is essential to diagnose the autoimmune nature of disease. Various immunofluorescence methods as well as molecular immunoassays, including enzyme-linked immunosorbent assay and immunoblotting, belong to the modern diagnostic algorithms for these disorders. There is still a considerable need to increase awareness of the rare autoimmune blistering diseases, which often show a severe, chronic-relapsing course, among physicians and the public. This review article describes the immunopathological features of autoimmune bullous diseases and the molecular immunoassays currently available for their diagnosis and monitoring.

Linear IgA bullous disease presenting as toxic epidermal necrolysis: a case report and review of the literature

A 91-year-old female presented with widespread skin sloughing and bullae clinically mimicking toxic epidermal necrolysis (TEN). The patient was on multiple antibiotics, including vancomycin and piperacillin/tazobactam. Histopathology and direct immunofluorescence were consistent with a diagnosis of linear IgA bullous disease (LABD). In a PubMed review of the literature from 1975 to the present, there have been 15 cases of LABD presenting as TEN clinically and with characteristic linear IgA deposits on direct immunofluorescence studies. Vancomycin and phenytoin were the most commonly implicated medications. Twelve patients saw a resolution or healing of skin lesions after discontinuation of the implicated medication. There were, however, 5 patients who died of complications related to their comorbidities. It is important to include LABD in the differential diagnosis when evaluating patients who clinically present with TEN.

Drug-induced linear IgA bullous dermatosis after discontinuation of cefuroxime axetil treatment

BACKGROUND

Linear immunoglobulin A (IgA) bullous dermatosis (LABD) is a rare autoimmune blistering disorder. The disease may be either idiopathic or druginduced. Over the past 30 years, approximately one hundred LABD cases have been described as induced by a wide range of drugs, chiefly antibiotics.

MAIN OBSERVATIONS

We report the case of 37-year-old woman who developed pruritic bullous lesions spread all over the body three weeks after her last dose of cefuroxime axetil. Antibiotic therapy was started due to rhino-sinusitis.

CONCLUSIONS

In most reported cases of drug-induced LABD, skin lesions occur within the time of drug administration. However, the onset of disease may be even after discontinuation of treatment. It seems that in such cases, other clinical conditions (like infection) act, as cofactors of immunologic response.