The Dapsone hypersensitivity syndrome revisited: a potentially fatal multisystem disorder with prominent hepatopulmonary manifestations

Treatment of Subcorneal Pustular Dermatosis without Dapsone: A Case Report and Review of the Literature

Subcorneal pustular dermatosis (SPD) is a rare neutrophilic dermatosis characterized by pustules on the trunk and intertriginous areas. While oral dapsone is the first-line treatment for SPD, alternative options are necessary for patients with glucose-6-phosphate dehydrogenase deficiency, drug hypersensitivity reactions, or refractory disease. To date, no consensus exists regarding next-best agents for SPD. In this report, we present a patient with significant SPD who developed dapsone hypersensitivity syndrome and then was successfully treated with colchicine and adalimumab. We propose that colchicine should be considered as a second-line treatment for SPD and present a therapeutic algorithm for clinicians to utilize when patients are not candidates for dapsone, have side effects requiring drug discontinuation, or have refractory disease.

Overview and Current Advances in Dapsone Hypersensitivity Syndrome

PURPOSE OF REVIEW

As a sulfone antibacterial agent, dapsone has been widely used to treat leprosy. Moreover, dapsone is also used in many immune diseases such as herpetic dermatitis because of its anti-inflammatory and immunomodulatory effects. However, dapsone can cause several adverse effects, the most serious being dapsone hypersensitivity syndrome. Dapsone hypersensitivity syndrome is characterized by a triad of eruptions, fever, and organ involvement, which limits the application of dapsone to some extent.

RECENT FINDINGS

In this article, we review current research about the interaction model between HLA-B*13:01, dapsone, and specific TCR in dapsone-induced drug hypersensitivity. In addition to the proposed mechanisms, we also discussed clinical features, treatment progress, prevalence, and prevention of dapsone hypersensitivity syndrome. These studies reveal the pathogenesis, clinical features, and prevalence from the perspectives of genetic susceptibility and innate and adaptive immunity in dapsone hypersensitivity syndrome, thereby guiding clinicians on how to diagnose, prevent, and treat dapsone hypersensitivity syndrome.

Existing and Investigational Medications for Refractory Chronic Spontaneous Urticaria: Safety, Adverse Effects, and Monitoring

Treatment of chronic spontaneous urticaria (CSU) is responsive to H1 antihistamines administered up to four times the recommended US Food and Drug Administration dose in approximately 50% of patients. However, when patients do not respond to these first-line agents, evidence-based guidelines using Grading of Recommendations, Assessment, Development, and Evaluations methodology have provided direction for second- and third-line treatments that can effectively treat patients with CSU. Some patients remain refractory to these advanced treatments; therefore, alternative treatments with a lower certainty of evidence may be necessary. Regardless of the therapies used to treat CSU patients, it is essential for clinicians to be knowledgeable about the mechanism of action, efficacy, and safety and monitoring recommendations of the treatments prescribed. This review provides a comprehensive review of the adverse effects and monitoring recommendations for agents in use for CSU treatment as well as those currently undergoing investigation for CSU treatment.

A comprehensive insight into the anti-inflammatory properties of dapsone

The 4,4'-diaminodiphenyl sulfone (DDS), also known as dapsone, is traditionally used as a potent anti-bacterial agent in clinical management of leprosy. For decades, dapsone has been among the first-line medications used in multidrug treatment of leprosy recommended by the World Health Organization (WHO). Shortly after dapsone's discovery as an antibiotic in 1937, the dual function of dapsone (anti-microbial and anti-inflammatory) was elucidated. Dapsone exerts its anti-bacterial effects by inhibiting dihydrofolic acid synthesis, leading to inhibition of bacterial growth, while its anti-inflammatory properties are triggered by inhibiting reactive oxygen species (ROS) production, reducing the effect of eosinophil peroxidase on mast cells and downregulating neutrophil-mediated inflammatory responses. Among the leading mechanisms associated with its anti-microbial/anti-protozoal effects, dapsone clearly has multiple antioxidant, anti-inflammatory, and anti-apoptotic functions. In this regard, it has been described in treating a wide variety of inflammatory and infectious skin conditions. Previous reports have explored different molecular targets for dapsone and provided insight into the anti-inflammatory mechanism of dapsone. This article reviews several basic, experimental, and clinical approaches on anti-inflammatory effect of dapsone.

Implementation of genetic screening test to reduce the incidence of dapsone hypersensitivity syndrome among patients with leprosy in Papua, Indonesia: a study protocol

INTRODUCTION

The mainstay of leprosy treatment is multidrug treatment (MDT), which contains rifampicin, dapsone and clofazimine. The occurrence of dapsone hypersensitivity syndrome (DHS), a sudden, potentially fatal and traumatic adverse reaction due to dapsone, may affect treatment adherence and may result in fatality if untreated. Before MDT administration, screening for HLA-B*13:01 in patients with leprosy can potentially reduce DHS risk. The study aims to assess the effectiveness of using a screening test for HLA-B*13:01 in reducing the incidence of DHS and to evaluate the feasibility of using the quantitative PCR-based screening tool as DHS predictors before dapsone administration using individual patient testing in a referral centralised-lab model.

METHODS AND ANALYSIS

A total of 310 newly diagnosed patients with leprosy will be recruited from health centres in two highly endemic districts in Indonesia. Dried blood will be taken on filter paper as the specimen receptacle to collect DNA from the patients and transported at room temperature to the leprosy referral laboratory before MDT administration. Checking for HLA-B*13:01 from human DNA is performed using the Nala PGx 1301 V.1 kit. The results will be shared with the leprosy health workers on the site via phone call and courier. Patients with a positive test result will be treated with MDT without dapsone, and patients with a negative result will be treated with complete MDT. Physical examination (weight, height, skin, muscle and nerve function examination), complete blood tests (including renal function test) will be carried out at baseline. Follow-up will be performed at the fourth and eighth weeks to observe any development of adverse drug reactions.

ETHICS AND DISSEMINATION

The ethical approval for the study was issued by the Ethical Committee of the National Institute of Health Research and Development, Ministry of Health, Indonesia. Written informed consent will be sought from all participants.

Dapsone Hypersensitivity Syndrome With Leukemoid Reaction and Severe Thrombocytosis

Hypersensitivity reactions to dapsone are common and potentially fatal adverse drug reactions. Herein, we report a case of a 45-year-old female who presented with fever, generalized desquamating rashes, and icterus three weeks after initiation of dapsone therapy for leprosy neuritis. She was diagnosed to have dapsone hypersensitivity syndrome (DHS) with leukemoid reaction and thrombocytosis. Dapsone was immediately discontinued, and she has treated with prednisolone 50 mg daily for a month and tapered over the next month. She has improved completely. DHS, leukemoid reaction, and severe thrombocytosis, or these adverse drug reactions to dapsone have rarely been reported.

Drug hapten-specific T-cell activation: Current status and unanswered questions

Drug haptens are formed from the irreversible, covalent binding of drugs to nucleophilic moieties on proteins, which can warrant adverse reactions in the body including severe delayed-type, T-cell mediated, drug hypersensitivity reactions (DHRs). While three main pathways exist for the activation of T-cells in DHRs, namely the hapten model, the pharmacological interaction model and the altered peptide repertoire model, the exact antigenic determinants responsible have not yet been defined. In recent years, progress has been made using advanced mass spectrometry-based proteomic methods to identify protein carriers and characterise the structure of drug-haptenated proteins. Since genome-wide association studies discovered a link between human leukocyte antigens (HLA) and an individual's susceptibility to DHRs, much effort has been made to define the drug-associated HLA ligands driving T-cell activation, including the elution of natural HLA peptides from HLA molecules and the generation of HLA-binding peptides. In this review, we discuss our current methodology used to design and synthesise drug-modified HLA ligands to investigate their immunogenicity using T-cell models, and thus their implication in drug hypersensitivity.

A Rare Case of Dapsone Hypersensitivity Syndrome and Leukemoid Reaction With Coexisting Hepatitis E in a Pediatric Patient

Dapsone is extensively used for a variety of infectious, immunological, and hypersensitivity disorders. Dapsone can cause several adverse effects, the most serious being dapsone hypersensitivity syndrome (DHS), which is potentially fatal. DHS is characterized by triad of eruptions, fever, and organ involvement (including liver, kidney, hematological system, etc.). DHS can develop several weeks to as late as 6 months after treatment initiation with dapsone. Here, we report a case of DHS and leukemoid reaction with coexisting hepatitis E in a 10-year-old girl. Three weeks prior to the current admission, she was treated with dapsone (1 mg/kg/day in two divided doses) for 8 days by a local doctor for lichen nitidus. She was managed successfully for DHS with intravenous (IV) steroids followed by the oral steroid. This case is being reported to highlight the importance to ensure timely diagnosis of DHS and its appropriate management. Patients started on dapsone for various clinical conditions need to be observed carefully for the development of the DHS. If this occurs, DHS can be mistaken for the progression of the primary disease. If dapsone is not withdrawn, it could have deleterious and potentially fatal effects due to major organ dysfunction.

Association Between HLA-B*1301 and Dapsone-Induced Cutaneous Adverse Drug Reactions: A Systematic Review and Meta-analysis

Importance

Dapsone-induced hypersensitivity syndrome (DHS) is a life-threatening adverse drug reaction. Based on available epidemiologic studies, HLA genotypes may play an important role in DHS.

Objective

To assess the association between HLA-B*1301 and dapsone-induced cutaneous adverse drug reactions (cADRs).

Data Sources

Human studies investigating associations between HLA-B*1301 and dapsone-induced cADRs were systematically searched without language restriction from the inception of each database until September 12, 2017, in PubMed, the Human Genome Epidemiology Network), and the Cochrane Library. Combinations of HLA genotypes, dapsone, and synonymous terms were used; reference lists were searched in selected articles.

Study Selection

Two reviewers identified studies investigating the associations between HLA-B*1301 and dapsone-induced cADRs that reported sufficient data for calculating the frequency of HLA-B*1301 carriers among case and control patients, in which all patients received dapsone before HLA-B*1301 screening. An initial search of the databases identified 391 articles, of which 3 studies (2 in Chinese populations and 1 in a Thai population) met the inclusion criteria.

Data Extraction and Synthesis

Overall odds ratios (ORs) with 95% CIs were calculated using a random-effects model to determine the association between HLA-B*1301 and dapsone-induced cADRs. Subgroup analyses by type of cADR were also performed. PRISMA guidelines were used to abstract and assess data.

Main Outcomes and Measures

Primary outcomes were associations between HLA-B*1301 and dapsone-induced cADRs in dapsone-tolerant controls. The outcomes are reported as overall OR. Statistical heterogeneity was assessed using the Q statistic and I2 tests.

Results

From the 3 included studies, there were 111 unique patients with dapsone-induced cADRs (subsequently used in the meta-analysis), 1165 dapsone-tolerant patients, and 3026 healthy controls. The cases included 64 men and 49 women (2 patients were missing from the meta-analysis; 1 each from 2 of the 3 studies); mean age was 39.7 years. An association between HLA-B*1301 and dapsone-induced cADRs was identified (summary OR, 43.0; 95% CI, 24.0-77.2). Subgroup analyses among types of cADRs produced similar findings in DHS (OR, 51.7; 95% CI, 16.9-158.5), dapsone-induced severe cADRs (Stevens-Johnson syndrome and toxic epidermal necrolysis [SJS/TEN] plus drug rash [adverse skin reaction to a drug] along with eosinophilia and systemic symptoms [DRESS]) (OR, 54.0; 95% Cl, 8.0-366.2), dapsone-induced SJS/TEN (OR, 40.5; 95% CI, 2.8-591.0), and dapsone-induced DRESS (OR, 60.8; 95% CI, 7.4-496.2). There was no heterogeneity (I2 = 0%, P = .38).

Conclusions and Relevance

Associations between HLA-B*1301 and dapsone-induced cADRs were found in dapsone-tolerant and healthy control groups. For patient safety, genetic screening for HLA-B*1301 in Asian populations before dapsone therapy is warranted.

An enhanced regimen as post-exposure chemoprophylaxis for leprosy: PEP+

The ongoing transmission of Mycobacterium (M.) leprae reflected in a very slow decline in leprosy incidence, forces us to be innovative and conduct cutting-edge research. Single dose rifampicin (SDR) as post-exposure prophylaxis (PEP) for contacts of leprosy patients, reduces their risk to develop leprosy by 60%. This is a promising new preventive measure that can be integrated into routine leprosy control programmes, as is being demonstrated in the Leprosy Post-Exposure Programme that is currently ongoing in eight countries.The limited (60%) effectiveness of SDR is likely due to the fact that some contacts have a preclinical infection beyond the early stages for which SDR is not sufficient to prevent the development of clinical signs and symptoms of leprosy. An enhanced regimen, more potent against a higher load of leprosy bacteria, would increase the effectiveness of this preventive measure significantly.The Netherlands Leprosy Relief (NLR) is developing a multi-country study aiming to show that breaking the chain of transmission of M. leprae is possible, evidenced by a dramatic reduction in incidence. In this study the assessment of the effectiveness of an enhanced prophylactic regimen for leprosy is an important component. To define the so called PEP++ regimen for this intervention study, NLR convened an Expert Meeting that was attended by clinical leprologists, public health experts, pharmacologists, dermatologists and microbiologists.The Expert Meeting advised on combinations of available drugs, with known efficacy against leprosy, as well as on the duration of the intake, aiming at a risk reduction of 80-90%. To come to a conclusion the Expert Meeting considered the bactericidal, sterilising and bacteriostatic activity of the potential drugs. The criteria used to determine an optimal enhanced regimen were: effectiveness, safety, acceptability, availability, affordability, feasibility and not inducing drug resistance.The Expert Meeting concluded that the enhanced regimen for the PEP++ study should comprise three standard doses of rifampicin 600 mg (weight adjusted when given to children) plus moxifloxacin 400 mg given at four-weekly intervals. For children and for adults with contraindications for moxifloxacin, moxifloxacin should be replaced by clarithromycin 300 mg (weight adjusted).

Dapsone Hypersensitivity Syndrome (DHS): A Detrimental Effect of Dapsone? A Case Report

BACKGROUND

Dapsone is a sulfone derived drug used in the treatment of leprosy and several chronic inflammatory dermatological diseases. Dapsone Hypersensitivity Syndrome (DHS) is characterized by fever, hepatitis, generalized exfoliative dermatitis and lymphadenopathy. It is rare and potentially fatal.

CASE REPORT

We present a case report of a 52 years old female with a recent history of antecedent dapsone exposure of 100 mg daily for 2 weeks. She developed fever 10 days after exposure to dapsone therapy and was treated in various primary and tertiary centers for features of sepsis. When she presented to us, clinical features of multi-organ dysfunction and intractable sepsis was evident. She was successfully managed with intravenous corticosteroids and other supportive therapy. This case of DHS is unique due to pulmonary, hepatic and colonic involvement in addition to secondary bacterial and fungal infection, which is associated with an increased risk of mortality.

CONCLUSION

As dapsone is mainstay in the treatment several infections and inflammatory conditions, further research is needed to characterize markers to diagnose DHS and to develop screening policies prior to initiation of dapsone therapy.

Dapsone and Nitroso Dapsone Activation of Naı̈ve T-Cells from Healthy Donors

Dapsone (DDS) causes hypersensitivity reactions in 0.5-3.6% of patients. Although clinical diagnosis is indicative of a hypersensitivity reaction, studies have not been performed to define whether dapsone or a metabolite activates specific T-cells. Thus, the aims of this study were to explore the immunogenicity DDS and nitroso DDS (DDS-NO) using peripheral blood mononuclear cells from healthy donors and splenocytes from mice and generate human T-cell clones to characterize mechanisms of T-cell activation. DDS-NO was synthesized from DDS-hydroxylamine and shown to bind to the thiol group of glutathione and human and mouse albumin through sulfonamide and N-hydroxyl sulphonamide adducts. Naïve T-cell priming to DDS and DDS-NO was successful in three human donors. DDS-specific CD4+ T-cell clones were stimulated to proliferate in response to drug via a MHC class II restricted direct binding interaction. Cross reactivity with DDS-NO, DDS-analogues, and sulfonamides was not observed. DDS-NO clones were CD4+ and CD8+, MHC class II and I restricted, respectively, and activated via a pathway dependent on covalent binding and antigen processing. DDS and DDS-NO-specific clones secreted a mixture of Th1 and Th2 cytokines, but not granzyme-B. Splenocytes from mice immunized with DDS-NO were stimulated to proliferate in vitro with the nitroso metabolite, but not DDS. In contrast, immunization with DDS did not activate T-cells. These data show that DDS- and DDS-NO-specific T-cell responses are readily detectable.

Dapsone hypersensitivity syndrome-related lung injury without eosinophilia in the bronchoalveolar lavage fluid

A 73-year-old man was admitted in respiratory failure that had subacutely progressed after five weeks of dapsone treatment for a skin rash. He also presented with fever, systemic erythroderma and liver dysfunction. Chest computed tomography showed diffuse reticular shadows with ground-glass opacity and bilateral mediastinal lymphadenopathy. Lymphocytes, but not eosinophils, were increased in the bronchoalveolar lavage fluid. Moreover, reactivation of human herpes virus-6 was confirmed on a paired serum test. Finally, we diagnosed the patient with dapsone hypersensitivity syndrome (DHS), a rare adverse event of this drug. Lung injury unaccompanied by eosinophilia in the bronchoalveolar lavage fluid is even more rare as a DHS-related lung manifestation.

Fulminant hepatitis linked to dapsone hypersensitivity syndrome requiring urgent living donor liver transplantation: a case report

Dapsone is a sulfone-type drug used widely for different infectious, immune, and hypersensitivity disorders as an antibacterial treatment alone or in combination for leprosy and sometimes for infected skin lesions. DHS is a severe idiosyncratic adverse reaction with multi-organ involvement. However, acute necrotic hepatitis requiring an emergent LT is rare. Herein, we report a case of 12-yr-old girl who suffered from fulminant hepatitis and multi-organ failure due to DHS for PPD. She was saved by emergent LDLT. A high index of suspicion and rapid diagnosis are necessary not to miss this potentially lethal but rare disease.

Double-blind placebo-controlled trial of dapsone in antihistamine refractory chronic idiopathic urticaria

BACKGROUND

Management of antihistamine refractory chronic idiopathic urticaria (CIU) has poorly defined therapeutic options.

OBJECTIVE

To evaluate the efficacy of dapsone (4,4'-diaminodiphenylsulfone) in antihistamine refractory CIU compared with placebo.

METHODS

Twenty-two patients with antihistamine refractory CIU were randomly assigned to 100 mg of dapsone daily or placebo for 6 weeks in a 14-week double-blind, placebo-controlled crossover trial. End points were measured from a daily diary that reflected the weekly hive score, the weekly itch score, and a visual analog scale (VAS) score. Secondary to a carryover effect, the first period results were analyzed as a parallel design that compared placebo with dapsone directly by using repeated-measures analysis.

RESULTS

After 6 weeks, the patients in the dapsone arm showed mean improvement over baseline in VAS (2.3 [95% CI, 0.6-4.1], P = .01), urticaria score (-3.5 [95% CI, -6.2 to -0.9], P = .01), and itch score (-4.8 [95% CI, -7.6 to -2.1], P = .001), whereas the placebo arm showed no improvement over baseline for VAS, urticaria, or itch scores. Dapsone showed greater improvement compared with placebo for itch (P = .047) and VAS (P = .04). Of the 22 patients, 3 showed complete resolution of hives and itch with dapsone, whereas 31% and 41% had ≥ 50% resolution of hives and itch, respectively. No serious adverse effects were observed with dapsone.

CONCLUSION

To our knowledge, this is the first double-blind, placebo controlled study of dapsone in CIU and indicates that dapsone has efficacy in patients with antihistamine refractory CIU.

Extensive pulmonary involvement with raltegravir-induced DRESS syndrome in a postpartum woman with HIV

An 18-year-old postpartum woman with HIV, on lamivudine-zidovudine, lopinavir-ritonavir and raltegravir, presented with a 1-week history of rash and fevers. Initially admitted to obstetrics and gynaecology service for treatment of possible endometritis, she was transferred to the HIV medicine service for high fever, respiratory distress, hypotension and tachycardia. On admission, she was febrile (102°F) with findings of cervical and submandibular lymphadenopathy, diffuse morbilliform rash, generalised pruritus, facial oedema, and oedematous hands and feet. Consultations to various specialty services were initiated to rule out infectious, dermatological, rheumatological and drug-induced aetiologies. On the fourth day of hospitalisation, laboratory findings of significant eosinophilia and hepatitis (alanine aminotransferase 147 IU/L and aspartate aminotransferase 124 IU/L), in conjunction with the identification of the timing of medication use, led to a diagnosis of DRESS (drug reaction with eosinophilia and systemic symptoms) syndrome secondary to raltegravir. After discontinuing raltegravir and starting prednisone, her DRESS symptoms completely resolved.

Mononucleosis-like drug rash: an interesting case presentation

Dapsone hypersensitivity syndrome (DHS) is a rare adverse effect of the commonly prescribed drug dapsone. We present a case of a 35-year-old male who was referred to us from the gastroenterologist with complaints of rash, nausea, vomiting, and jaundice since 2 days with a provisional differential diagnosis of infectious mononucleosis or viral exanthema. On enquiry patient gave history of taking dapsone a week prior for refractory urticaria. After thorough investigations we diagnosed him with DHS. This syndrome occurs in a relatively small proportion of patients, but it is associated with considerable morbidity and mortality. The reason for presenting this case is to remind physicians of the unpredictability and potential severity of this reaction which makes it a major concern in clinical practice.

Hypersensitivity reactions to non beta-lactam antimicrobial agents, a statement of the WAO special committee on drug allergy

Antibiotics are used extensively in the treatment of various infections. Consequently, they can be considered among the most important agents involved in adverse reactions to drugs, including both allergic and non-allergic drug hypersensitivity [J Allergy Clin Immunol 113:832–836, 2004]. Most studies published to date deal mainly with reactions to the beta-lactam group, and information on hypersensitivity to each of the other antimicrobial agents is scarce. The present document has been produced by the Special Committee on Drug Allergy of the World Allergy Organization to present the most relevant information on the incidence, clinical manifestations, diagnosis, possible mechanisms, and management of hypersensitivity reactions to non beta-lactam antimicrobials for use by practitioners worldwide.

Dapsone hypersensitivity syndrome: A rare life threatening complication of dapsone therapy

Dapsone can cause several adverse effects, the most serious being dapsone hypersensitivity syndrome (DHS), which is potentially fatal. Here we report a case of severe, life threatening dapsone systemic hypersensitivity syndrome in a 17-year-old male who presented with high grade fever, eosinophilia, lymphadenopathy, skin rash, hepatitis and encephalopathy, which was managed successfully with oral steroids. The case is being reported to emphasize the need for timely diagnosis and prompt treatment of this rare complication for successful outcomes. DHS is also reviewed in brief.

Hepatic necrosis associated with drug-induced hypersensitivity syndrome

Drug-induced hypersensitivity syndrome (DIHS; also known as drug reaction with eosinophilia and systemic symptoms [DRESS]) is a life-threatening condition first described by Chaiken et al. in 1950. It is characterized by extensive mucocutaneous rash; fever; lymphadenopathy; hepatitis; hematological abnormalities; damage to several organs such as kidney, heart, lungs, and pancreas; and possible reactivation of human herpesvirus-6 (HHV-6) or other herpes virus. Rare and severe cases may present hepatic necrosis, and about 15% of them result in death or liver transplantation. A hallmark of this syndrome is the late onset of symptoms after the drug exposure. The most common culprit drugs are the aromatic anticonvulsants (in almost 30% of the cases) and the antibiotics (which in some series represent 20% of the cases). The authors report a case of a 41-year-old female who presented to the emergency department with erythroderma, acute hepatitis, acute pancreatitis and acute renal failure, and was then treated with corticosteroid after the diagnosis of DIHS/DRESS. A specific culprit drug could not confidently be determined due to the presence of multiple drugs used by the patient. The clinical and laboratory outcome was apparently satisfactory, but unexpectedly, on the sixth day of hospitalization, the patient complained of nonspecific malaise, drowsiness, which progressed in a few hours with signs and symptoms of hepatic failure, refractory shock, and death. The autopsy findings showed submassive hepatic necrosis, and the immediate cause of death was attributed to hepatic failure.

Cervical lymphadenopathy mimicking angioimmunoblastic T-cell lymphoma after dapsone-induced hypersensitivity syndrome

A 36-year-old woman presented with erythematous confluent macules on her whole body with fever and chills associated with jaundice after 8 months of dapsone therapy. Her symptoms had developed progressively, and a physical examination revealed bilateral cervical lymphadenopathy and splenomegaly. Excisional biopsy of a cervical lymph node showed effacement of the normal architecture with atypical lymphoid hyperplasia and proliferation of high endothelial venules compatible with angioimmunoblastic T-cell lymphoma. However, it was assumed that the cervical lymphadenopathy was a clinical manifestation of a systemic hypersensitivity reaction because her clinical course was reminiscent of dapsone-induced hypersensitivity syndrome. A liver biopsy revealed drug-induced hepatitis with no evidence of lymphomatous involvement. Intravenous glucocorticoid was immediately initiated and her symptoms and clinical disease dramatically improved. The authors present an unusual case of cervical lymphadenopathy mimicking angioimmunoblastic T-cell lymphoma as an adverse reaction to dapsone.

Models of asthma: density-equalizing mapping and output benchmarking

Despite the large amount of experimental studies already conducted on bronchial asthma, further insights into the molecular basics of the disease are required to establish new therapeutic approaches. As a basis for this research different animal models of asthma have been developed in the past years. However, precise bibliometric data on the use of different models do not exist so far. Therefore the present study was conducted to establish a data base of the existing experimental approaches. Density-equalizing algorithms were used and data was retrieved from a Thomson Institute for Scientific Information database. During the period from 1900 to 2006 a number of 3489 filed items were connected to animal models of asthma, the first being published in the year 1968. The studies were published by 52 countries with the US, Japan and the UK being the most productive suppliers, participating in 55.8% of all published items. Analyzing the average citation per item as an indicator for research quality Switzerland ranked first (30.54/item) and New Zealand ranked second for countries with more than 10 published studies. The 10 most productive journals included 4 with a main focus allergy and immunology and 4 with a main focus on the respiratory system. Two journals focussed on pharmacology or pharmacy. In all assigned subject categories examined for a relation to animal models of asthma, immunology ranked first. Assessing numbers of published items in relation to animal species it was found that mice were the preferred species followed by guinea pigs. In summary it can be concluded from density-equalizing calculations that the use of animal models of asthma is restricted to a relatively small number of countries. There are also differences in the use of species. These differences are based on variations in the research focus as assessed by subject category analysis.

Editorial: Experimental models of asthma

Since 2002, a workshop entitled “Asthma in animal models” has been held once a year in Hannover, Germany. It is organized by the Fraunhofer Institute of Toxicology and Experimental Medicine in collaboration with the collaborative research centre “Sonderforschungsbereich” 587, “Immune reactions of the lung in infection and allergy” (Hannover Medical School). The aim of these meetings is an intense scientific exchange between researchers and clinicians coming from academic or industrial background. Over the years the topics within the extensive field of asthma and COPD have ranged from methodological aspects to the influence of infections and environmental factors up to perspectives in the development of new therapeutic strategies.

Treatment strategies in mucous membrane pemphigoid

Mucous membrane pemphigoid (MMP) is an autoimmune blistering disorder that is characterized by subepithelial bullae. Various basement membrane zone components have been identified as targets of autoantibodies in MMP. Considerable variability exists in the clinical presentation of MMP. Mucous membranes that may be involved include the oral cavity, conjunctiva, nasopharynx, larynx, esophagus, genitourinary tract, and anus. A multidisciplinary approach is essential in the management of MMP. Early recognition of this disorder and treatment may decrease disease-related complications. The choice of agents for treatment of MMP is based upon the sites of involvement, clinical severity, and disease progression. For more severe disease, or with rapid progression, systemic corticosteroids are the agents of choice for initial treatment, combined with steroid-sparing agents for long-term maintenance. Due to the rarity of this disease, large controlled studies comparing the efficacy of various agents are lacking.

Drug allergy: an updated practice parameter

Adverse drug reactions (ADRs) result in major health problems in the United States in both the inpatient and outpatient setting. ADRs are broadly categorized into predictable (type A and unpredictable (type B) reactions. Predictable reactions are usually dose dependent, are related to the known pharmacologic actions of the drug, and occur in otherwise healthy individuals, They are estimated to comprise approximately 80% of all ADRs. Unpredictable are generally dose independent, are unrelated to the pharmacologic actions of the drug, and occur only in susceptible individuals. Unpredictable reactions are subdivided into drug intolerance, drug idiosyncrasy, drug allergy, and pseudoallergic reactions. Both type A and B reactions may be influenced by genetic predisposition of the patient

Dermatologic disorders and the liver

Chronic liver disease is associated with several cutaneous manifestations. Although many of these changes are nonspecific, some are associated with distinct liver diseases and correlate with the severity of hepatic pathology. Often the first clue to a liver disease is manifested through skin. Although cirrhosis is associated with spider nevi and palmar erythema, disorders can result in noncirrhotic cutaneous manifestations. It is important for physicians to be familiar with the spectrum of these manifestations, to recognize, help detect, and treat the underlying hepatic disease. This article reviews the medical literature and discusses the spectrum of dermatologic manifestations of liver disorders and their pathogenesis, significance, and treatment.

Complete atrioventricular block associated with dapsone therapy: a rare complication of dapsone-induced hypersensitivity syndrome

Dapsone is still widely used for a range of infectious and inflammatory diseases. A potential severe side-effect, known as dapsone-induced hypersensitivity syndrome (DHS), may occur. DHS is characterized by fever, skin rashes, lymphadenopathy and multiorgan dysfunction manifesting as hepatitis, cholangitis, pneumonitis, colitis, thyroiditis and myocarditis. However, DHS-associated complete atrioventricular block has not previously been reported. We describe here a 45-year-old Chinese woman who developed DHS after 5 weeks of dapsone therapy for pustular palmoplantar psoriasis. In addition to typical DHS symptoms, she experienced several episodes of syncope as a result of complete atrioventricular block which was successfully reversed with a permanent pacemaker implantation.

Dapsone hypersensitivity syndrome causing disseminated intravascular coagulation

Dapsone hypersensitivity syndrome is an idiosyncratic reaction to this drug and can present with different clinical manifestations of varying severity. We describe a patient with disseminated intravascular coagulation (DIC) as an adverse reaction to dapsone. To the best of our knowledge, this is the first time it has been described in the literature. She presented with fever, rash and abdominal pain; she also had marked eosinophilia and features suggestive of oxidative haemolysis. Her course was complicated by DIC, splenic infarction and gastrointestinal bleeding. Extensive investigations did not reveal any alternative aetiology. She was initially treated with supportive measures and folic acid; steroids were administered later, following clinical deterioration. There was gradual improvement and the steroids were tapered. The patient recovered fully and remains well; her underlying chronic dermatologic condition is under satisfactory control with other medications.

Inter-disease comparison of research quantity and quality: bronchial asthma and chronic obstructive pulmonary disease

BACKGROUND

The two obstructive airway diseases bronchial asthma and chronic obstructive pulmonary disease (COPD) represent major global causes of disability and death. Whereas COPD research was largely underfunded in the 1980s and 1990s, increased funding activities have been initiated since the year 2000. However, detailed scientometric data on the development of research for asthma and COPD have not been generated so far.

METHODS

The present scientometric study was conducted to establish a database of research quantity and quality in the 20-year period between 1987 and 2006 using the Web of Science information system and the United Kingdom and Germany for comparison of research activities.

RESULTS

The information database Web of Science was screened and during the period from 1987 to 2006 a number of 8,874 items related to asthma was published by UK affiliations. Of these, 1,824 were published in cooperation with a total of 86 other countries. This is a ratio of 20.55%. In the same period, 3,341 items were published by German institutions (923 in cooperation with 56 other countries, ratio of 27.63%). Citation analysis demonstrated an average citation of 24.48 per UK article and 17.62 per German article. For COPD, 2,179 items were published by UK affiliations and 689 items by German institutions. Of the UK COPD publications, 570 were published in cooperations with 47 countries (ratio of 22.95 %). By contrast, 218 of the 689 German COPD articles were published with 29 other countries (ratio of 25.49%). When citation analysis was performed, average citation ratios of 18.93 for the UK and 10.61 for German were found.

CONCLUSION

Summarizing this first country-specific comparative benchmarking analysis for obstructive pulmonary diseases it can be concluded that (1) asthma research dominated in the past 20 years; (2) COPD research gained importance in the field since the end of the 1990s; (3) there are large differences present in the research output between the two high-income countries examined.