[Delayed-type cutaneous drug reactions. Pathogenesis, clinical features and histology]

BACKGROUND

Cutaneous reactions to drugs can be subdivided in different ways. In addition to the standard classification according to the etiopathogenesis there are also classifications based predominantly on morphological criteria. The majority of drug-related cutaneous adverse reactions are immunological reactions which are collectively classified under the term hypersensitivity. These reactions are based on drug-specific immunoglobulin E (IgE) or cell-mediated mechanisms, not on the mechanism of action of the drug and are unpredictable. Delayed type reactions to drugs are forms of type IV T-cell mediated hypersensitivity. A prerequisite is a stable association of a pharmaceutical substance with a protein so that hapten-protein conjugates can be produced. The most common clinical symptom is maculopapular (morbilliform) drug-related exanthema. This article also examines lichen planus like drug reaction and drug-induced (hematogenic) allergic contact dermatitis in more detail.

DIAGNOSTICS

The diagnostics are never trivial but also include the differentiation from viral exanthema and initial phases of severe cutaneous adverse reactions, such as toxic epidermal necrolysis. In addition to the morphological classification, the final diagnosis encompasses the interpretation of histopathological alterations in the skin biopsy, analysis of patient medication history, laboratory results and inclusion of data from the literature. Patch tests can also have additional diagnostic benefits. In vitro tests which involve the cellular incubation of the drug responsible should be reserved for specialized laboratories. A prerequisite for successful treatment is immediate termination of the drug responsible.

THERAPY AND PROGNOSIS

Therapy is symptomatic with topical and also short-term systemic steroids and antihistamines. The prognosis is very good.

Epidemiology of cutaneous drug-induced reactions

Cutaneous reactions represent in many surveillance systems, the most frequent adverse events attributable to drugs. The spectrum of clinical manifestations is wide and virtually encompasses any known dermatological disease. The introduction of biological agents and so-called targeted therapies has further enlarged the number of reaction patterns especially linked with cytokine release or in balance. The frequency and clinical patterns of cutaneous reactions are influenced by drug use, prevalence of specific conditions (e.g., HIV infection) and pharmacogenetic traits of a population, and they may vary greatly among the different populations around the world. Studies of reaction rates in cohorts of hospitalized patients revealed incidence rates ranging from, 1 out 1000 to 2 out 100 of all hospitalized patients. For drugs such as aminopenicillines and sulfamides the incidence of skin reactions is in the order of 3-5 cases out of 100 exposed people. Although the majority of cutaneous reactions are mild and self-limiting, there are reactions such as Stevens Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reaction with eosinophilia and systemic symptoms (DRESS) which are associated with significant morbidity and mortality. Surveillance systems routed on sound epidemiologic methodology, are needed to raise signals and to assess risks associated with specific reactions and drug exposures. Identification of risk factors for adverse reactions and appropriate genetic screening of groups at higher risk may improve the outcomes of skin reactions.

[Rosacea: Clinical features and classification]

Rosacea is a frequent chronic dermatological disorder mainly affecting the face. Since it affects the appearance, it can be very distressing for the patient leading to psychosocial disturbances. Rosacea occurs in adults, peaking between 40 and 50 years of age. The course of rosacea is quite variable and the disease may stop at any stage. Generally, three main stages are differentiated: erythemato-teleangiectatic rosacea (rosacea stage I), papulopustular rosacea (rosacea stage II), hyperglandular-hypertrophic rosacea (rosacea stage III). Besides these main manifestations numerous special forms exist, which often lead to difficulties in the differential diagnoses and require specific therapeutic strategies. These include rosacea conglobata, rosacea fulminans, granulomatous rosacea, persisting edema, (Morbihan disease), gram negative rosacea, ocular rosacea, and steroid rosacea. Recently increasing numbers of patients have been observed, whose rosacea was were induced by inhibitors of epidermal growth factors (cetuximab, geftinib) used as chemotherapy in patients with different malignancies. These side effects have been described as acneiform eruptions but at least some of the described patients have a rosacea-like appearance; therefore, this form can be classified as a subset of drug induced rosacea.

[The spectrum of drug eruptions]

Drug eruptions are frequently encountered and they represent "diseases of medical progress". They are expected in about 2% of treated patients. Their putative diagnosis is based on a set of imputability factors. Several distinct drug-induced skin disorders are identified. They are initially recognized from personal experience, but the implication to a specific drug derives from the collective experience of published evidence. Their histopathological aspect is often evocative or demonstrative for the nature of the dermatosis. Some drug eruptions follow an indolent course, while others are life-threatening.

Physiopathology of adverse cutaneous drug reactions--applied perceptions: part I

Adverse cutaneous drug reactions are common, but their physiopathology is largely elusive. The authors assess various reactions to facilitate their diagnosis and treatment. Some of the common reaction patterns are included with the prime objective of highlighting their physiopathology.

NKp46+ cells express granulysin in multiple cutaneous adverse drug reactions

BACKGROUND

The spectrum of cutaneous adverse drug reactions (cADRs) ranges from benign presentations to severe life-threatening forms such as toxic epidermal necrolysis (TEN). In TEN, granulysin has been shown to be the key cytotoxic molecule. Still, little is known about the expression of granulysin in other cADRs. As an important source of granulysin, natural killer (NK) cells are of major interest in cADRs. Recently, NKp46 has been identified as the most selective NK-cell marker. However, the role of NKp46(+) cells in cADRs and their contribution to granulysin expression remain to be elucidated.

METHODS

Immunohistochemical and immunofluorescence staining of tissue sections from multiple cADRs were quantitatively and qualitatively evaluated. Further, in vivo and in vitro drug-stimulation tests were performed.

RESULTS

Granulysin is expressed at different levels in multiple cADRs both by NKp46(+) cells and by CD8(+) T cells. Even in mild forms of cADRs, granulysin can be induced in vivo and in vitro in a drug-specific manner. NKp46(+) cells were found to infiltrate the dermal/epidermal junction particularly in TEN.

CONCLUSION

The impressive clinical differences of cADRs may not be uniquely explained by the expression of granulysin. Additional factors such as drug-specific activation and recruitment of NKp46(+) cells to the epidermis may play a role in determining the severity of cADRs. Therefore, unraveling the effects of drugs on NK-cell activation and trafficking may help to better understand the cytotoxic mechanisms behind cADRs.

A new proposal for a clinical-oriented subclassification of baboon syndrome and a review of baboon syndrome

OBJECTIVE

To review baboon syndrome (BS).

DATA SOURCES

Date sources were obtained from PubMed and Google Scholar: Photographs of baboon syndrome were obtained from our patient.

STUDY SELECTIONS

PubMed and Google Scholar were searched up to June 30, 2010. The search terms were "baboon syndrome", "SDRIFE" and "thimerosal allergy". Reverse references from relevant articles and Google Scholar were also used. As BS is a classical disease and cases of offending agents were relatively old, some references were more than five years old. In order to gather as many cases of offending agents as possible, more than 50 references were collected.

RESULTS AND CONCLUSION

We divided BS into as 4 groups; classical baboon syndrome, topical drug-induced baboon syndrome, systemic drug-induced baboon syndrome and symmetrical drug-related intertriginous and flexural exanthema (SDRIFE). The pathomechanism of BS is still unknown. A delayed type of hypersensitivity reaction, a recall phenomenon, pharmacologic interaction with immune-receptors and anatomical factors may be involved in the causation of BS.

[Adverse cutaneous reactions to drugs among hospitalized patients: a one year surveillance]

BACKGROUND

Adverse cutaneous reactions to Drugs (CDRs) are of particular interest among all adverse Drug reactions (ADR) due to their frequency, potential severity and because of the importance of an early diagnosis. Antimicrobial agents, anticonvulsants and non-steroidal anti-inflammatory Drugs are the Drugs associated to the highest risk of CDRs.

AIM

To assess CDRs in hospitalized patients and identify the Drugs involved.

MATERIAL AND METHODS

All patients hospitalized in the Hospital de Clínicas in Montevideo, Uruguay, with suspected CDRs, detected during one year, were included in this prospective study. The imputability was established using the Karch and Lasagna algorithm modified by Naranjo. We analyzed age, gender, Drugs involved, causal disease, severity, latency and evolution.

RESULTS

Seventeen patients, aged 17 to 85 years (15 females) with CDRs were identifed. Twelve had morbilliform exanthemas, four had reactions with eosinophilia and systemic symptoms and one had a Stevens Johnson syndrome. The Drugs involved were antimicrobials in nine cases, hypouricemic agents in four cases, anticonvulsants in three cases and aspartic insulin in one. Twelve patients had a life threatening reaction and one required admission to the intensive care unit. No deaths occurred.

CONCLUSIONS

CDRs were more common in women and most of them were caused by antimicrobial agents.

A mechanism-based classification of dermatologic reactions to biologic agents used in the treatment of cutaneous disease: Part 1

Biologic therapies are an efficacious new method of controlling a number of chronic conditions. Data regarding these medications continues to emerge, giving clinicians a greater understanding of their side effects profiles. The biologic agents used in dermatology, particularly the tumor necrosis factor-alpha inhibitors, have a number of varied dermatologic side effects. In this two-part article, we perform a review of literature regarding the cutaneous side effects of infliximab, etanercept, adalimumab, rituximab, efalizumab, and alefacept. In Part 1, we will discuss cutaneous infections, malignancy, rebound phenomenon, eczema, atopic dermatitis, lichenoid reactions, granulomatous disease, pruritus, acne, and progressive multifocal leukoencephalopathy.

Drug-Induced Psoriasis: An Evidence-Based Overview and the Introduction of Psoriatic Drug Eruption Probability Score

Psoriasis is a common skin disorder that needs a long-term management, not only because, of its prevalence but also because of the profound impact it can have on patients quality of life. Drugs may result in exacerbation of a preexisting psoriasis, in induction of psoriatic lesions on clinically uninvolved skin in patients with psoriasis, or in precipitation of the disease in persons without family history of psoriasis or in predisposed individuals. The knowledge of the drugs that may induce, trigger, or exacerbate the disease is of primary importance in clinical practice. By reviewing the literature, there are many reports on drug-induced psoriasis, but the data are not univocal. We propose, when possible, the use of a probability score from the authors to obtain a better classification and further understanding of drug-induced psoriasis.

[Retrospective analysis of adverse cutaneous drug reactions in patients hospitalized in Department of Dermatology and Venereology of Pomeranian Medical University in 1996-2006]

INTRODUCTION

Every adverse and undesirable event observed after administration of the therapeutic dose of the drug is defined as adverse drug reaction. The aim of the study was to evaluate the incidence frequency of cutaneous adverse drug reactions, to define the drugs inducing such reactions and to define the type of the most frequently found lesions in patients admitted to Department of Dermatology and Venereology of Pomeranian Medical University in Szczecin (PAM) in 1996-2006.

MATERIAL AND METHODS

A retrospective analysis of medical files of the patients, who were hospitalized in the Department of Dermatology and Venereology of PAM in Szczecin in 1996-2006, was carried out. Due to cutaneous adverse drug reactions, 386 patients were hospitalized. They made 4.25% of all admitted to our Department.

RESULTS

These reactions were found more frequently in females (65.5%) than in males (34.5%). Non-steroidal anti-inflammatory drugs induced adverse events most frequently (37.6%), followed by aminopenicillin antibiotics, particularly amoxycillin-containing agents, responsible for 25.8% of these reactions. Other antibiotics were responsible for undesirable events less frequently--9.6%. Macular and maculopapular rashes were the most frequently observed adverse cutaneous drug reactions (42.0% of the cases), followed by acute urticaria and Quincke's oedema (39.1% of all reactions), whereas contact dermatitis after topical drugs was found in 8.0% of the cases.

CONCLUSIONS

Cutaneous adverse drug reactions were mainly induced by non-steroidal anti-inflammatory drugs and aminopenicillin antibiotics. The most frequent forms of cutaneous adverse drug reactions were maculopapular rashes, acute urticaria and Quincke's oedema.

Cutaneous reactions to drugs in children

Cutaneous eruptions are a commonly reported adverse drug reaction. Cutaneous adverse drug reactions in the pediatric population have a significant impact on patients' current and future care options. A patient's recollection of having a "rash" when they took a medication as a child is a frequent reason for not prescribing a particular treatment. The quick detection and treatment of cutaneous adverse drug reactions, plus identification of the causative agent, are essential for preventing the progression of the reaction, preventing additional exposures, and ensuring the appropriate use of medications for both the current condition and others as the patient ages. The purpose of this review is to discuss a reasonable approach to recognition and initial management of cutaneous adverse drug reactions in children.

Classification and management of skin, hair, nail and mucosal side-effects of epidermal growth factor receptor (EGFR) inhibitors

Inhibitors of epidermal growth factor receptor (EGFR) are commonly used as therapeutic agents in oncology. In contrast to currently used oncological treatments, these inhibitors almost always cause skin- and skin adnex toxicity. About 85% of treated patients develop to a more or lesser extent an acneiform eruption. Xerosis cutis and painful nail disorders occur in, respectively, 35% and 10-15% of all treated patients. Also hair and mucosal changes have been reported, although to a lesser extent. These skin- and skin adnex toxicities are reversible after withdrawal of treatment, but are seldom a reason to stop or interrupt therapy. This review outlines the classification, the pathogenesis and therapy of these skin, hair, nail and mucosal changes due to EGFR inhibition. Informing the patient and management of these side-effects is very important to reduce discomfort and as such to increase compliance to therapy.

Management of Rash and Other Toxicities in Patients Treated with Epidermal Growth Factor Receptor—Targeted Agents

Inhibition of the epidermal growth factor receptor (EGFR) represents one of the most important avenues for research and development in the field of cancer therapy. The EGFR is a member of the ErbB receptor tyrosine kinase (TK) family, which also includes ErbB-2 (HER2/neu), ErbB-3 (HER3), and ErbB-4 (HER4). Current EGFR therapies available for use include monoclonal antibodies, such as cetuximab, and small-molecule EGFR TK inhibition by agents such as erlotinib. Side effects of these agents include dermatologic manifestations without the bone marrow suppressive properties of chemotherapy. Understanding of rash and how it relates to EGFR inhibitor toxicity and, perhaps more importantly, EGFR inhibitor response must be more clearly defined with clinical trials. The optimum management of rash in patients receiving anti-EGFR therapy remains somewhat controversial; this is secondary to imprecise classification of rash as well as the lack of clinical trials to determine the most appropriate treatment algorithm for these patients. We propose a treatment strategy to help aggressively treat dermatologic side effects allowing patients to continue receiving therapy without dose interruption or drug discontinuation.

Drug rash with eosinophilia and systemic symptoms vs toxic epidermal necrolysis: the dilemma of classification

According to contemporary vernacular, when the cutaneous manifestations of drug rash with eosinophilia and systemic signs (DRESS) syndrome are those of Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN), the condition is defined as "DRESS syndrome with severe cutaneous reactions". In this article, we have presented arguments for and against including patients with skin lesions of the SJS/TEN syndromes who also have fever (practically all of the patients) and internal organ involvement (most of the patients) under the definition of DRESS syndrome. After weighing the arguments for and against this alteration of definition, we conclude that it makes more sense for patients with SJS/TEN to be classified as such and not be lumped together under the misleading label of DRESS syndrome.

EGFR-targeted therapy for patients with colorectal cancer: patient management and future directions

The epidermal growth factor receptor (EGFR) signaling pathway is of particular relevance for patients with colorectal cancer (CRC); preclinical data indicate a role for EGFR in tumor cell growth, invasion, metastasis, and tumor angiogenesis. The goal of this program is to provide an overview of the EGFR signaling pathway as well as current and future treatment options for EGFR-targeted therapy in patients with CRC.

Drug eruptions: approaching the diagnosis of drug-induced skin diseases

Adverse drug reactions are a major problem in drug therapy, and cutaneous drug reactions account for a large proportion of all adverse drug reactions. Cutaneous drug reactions are also a challenging diagnostic problem since they can mimic a large variety of skin diseases, including viral exanthema, collagen vascular disease, neoplasia, bacterial infection, psoriasis, and autoimmune blistering disease, among others. Furthermore, determining that a particular medication caused an eruption is often difficult when the patient is taking multiple drugs. In this review, we will describe and illustrate a thoughtful, comprehensive, and clinical approach to the diagnosis and management of adverse cutaneous drug reactions. A morphologic approach to drug eruption includes those that are classified as maculopapular, urticarial, blistering or pustular with or without systemic manifestations. Exanthematous drug eruptions, drug hypersensitivity syndrome, urticaria and angioedema, serum sickness-like reactions, fixed drug eruptions, drug-induced autoimmune blistering diseases, Stevens-Johnson syndrome, toxic epidermal necrolysis, drug-induced acne, acute generalized exanthematous pustulosis, lichenoid drug eruptions and photosensitivity eruptions will be discussed.

[Tissue toxicity of antiseptics]

AIM

Local antiseptics are used for desinfection of skin and for lavage of wounds. The aim of this study was to determine the tissue toxicity of different antiseptics and to measure the irritation score (IS) and the irritation threshold (IT) for each substance.

METHOD

The tissue compatibilities of Dibromol, Kodan, Jodobac, Octenisept, Lavasept 0.2 %, hydrogen peroxide, chlorhexidindigluconate 0.5 % and 2-propanol 60 % were evaluated in the in vivo hens eggs chorion-allantoic membrane test (HET-CAM).

RESULTS

We found the most severe tissue toxicity for chlorhexidin digluconate 0.5 % (IS 20) and Kodan (IS 18). Irritating values were found for Dibromol (IS 14), Octenisept (IS 14) and 2-propanol 60 % (IS 13). Moderate vascular injuries were caused by Jodobac (IS 2). In the HET-CAM test Lavasept 0.2 % (IS 0) and hydrogen peroxide (IS 0) showed no tissue toxicity.

CONCLUSION

Our results show that some of the tested antiseptics might cause severe vascular injuries as a sign of tissue toxicity. The tissue compatibility of Lavasept 0.2 % and hydrogen peroxide is much better than the compatibility of the other tested substances. With focus on the literature and our results, Lavasept 0.2 % can be recommended as the local antiseptic of choice.

[Drug eruptions]

In the following paper, there have been discussed the mechanisms of reactions which may result from adverse drug effects. In particular, the paper shows a clinical picture of skin lesions and various dermatological entities in which drugs are triggering factors.

Drug eruptions and other adverse drug effects in aged skin

The elderly are at higher risk for suffering the annoying and hazardous skin reactions that are associated with drug therapy. If a serious reaction occurs, the aged are also at higher risk for major morbidity and mortality compared with younger individuals. Early consideration of a drug cause and prompt cessation of all potentially associated drugs may improve a patient's outcome. Thus, a prompt, careful, and accurate characterization of a drug-related reaction is important in optimizing patient care, along with close monitoring for associated internal toxicities and other medical complications of severe cutaneous reactions.

Comparison of the statistical efficiency of case-crossover and case-control designs: application to severe cutaneous adverse reactions

Although case-crossover analyses have lately emerged as an alternative to case-control analyses in epidemiological studies, it is not yet known in which situations they give reliable conclusions. In this work, the case-crossover and the case-control designs were first compared on the basis of a dataset from a published study of severe cutaneous adverse reactions resulting from drug exposures of various durations and prevalences of use (245 cases, 1147 controls, and exposures to 23 drug classes). Next, the statistical efficiency of each design was compared via Monte Carlo simulations. Eight of the 13 risk factors identified by case-control analysis of the published data were also identified by the case-crossover analysis, with fairly good agreement on ranks of risk estimates (Spearman's correlation coefficient = 0.71, P < 0.001 ). Simulation studies showed that for relative risks below 8, the case-crossover design (250 cases, 4 control periods/case) had a higher power than the case-control design (250 cases, 4 controls/case), and that the case-crossover design was more conservative than the case-control design for prevalences of drug use below 10%. We conclude that the case-crossover design is not suitable for long-term exposures, but is an appropriate alternative for assessing rare risks associated with transient to short-term exposures.

Physiopathology and treatment of severe drug eruptions

This review will focus on recent advances concerning the most severe cutaneous drug reactions: the Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug reactions with eosinophilia and systemic symptoms. The most significant progress concerned the demonstration that drugs more often than reactive metabolites are immunogenic and induced several kinds of responses. These findings provided the rationale for using new therapeutic approaches, which will be discussed.

Neutrophilic fixed drug eruption

A 49-year-old man presented with a reproducible, localized amoxycillin-clavulanic acid-induced eruption. The histopathology from lesional skin revealed a neutrophilic dermatosis. These histological findings have not been reported in previous fixed drug eruptions. A brief review is undertaken comparing fixed drug eruption and the group of neutrophilic dermatoses with our case presentation. We propose a new entity of neutrophilic fixed drug eruption.

[Cutaneous adverse drug reactions: enhanced imputation score by skin testing]

INTRODUCTION

A careful diagnosis and the identification of the causative drug after a cutaneous adverse reaction can avoid relapses. Skin tests facilitate the identification of the causative molecule by producing a hypersensitivity reaction at the application site. Adverse drug reactions are reported to Pharmacovigilance Centres who determine the imputation score of the suspected drugs. The aim of this study was to assess to what extent skin testing after a suspected allergic drug reaction can be helpful to identify the causative drug and whether an impact on the final imputation score could be evidenced.

METHOD

A 18-month prospective study was performed. All patients with a history of cutaneous adverse drug reaction of suspected immunoallergic origin were included provided skin tests could be performed within 6 to 12 weeks after the adverse drug reaction. The imputation score was determined using the French imputation method prior to and after skin testing.

RESULTS

Thirthy-nine patients were included in the study. Positive skin tests were observed in 11 of 20 patients with a C2S2 (I2: plausible) initial imputation score and in 6 of 15 patients with a C2S1 (I1: doubtful) initial imputation score. One patient with a C1S1 (I1: doubtful) initial imputation score had positive skin tests.

DISCUSSION

The results of skin tests helped change the imputation score of the suspected drug in 18 patients out of 39. In 55 p. 100 of cases, the imputation score was increased from C2S2 (I2) to C2S3 (I3: likely) and from C2S1 (I1) to C2S3 (I3) in 40 p. 100 of cases. The increase in imputation scores was helpful to improve warning signals after an immunoallergic reaction. Skin tests led to a more accurate diagnosis in 50 p. 100 of cases. Thus, more adequate advices for further drug treatment were possible, particularly in avoiding the irrelevant prohibition of innocent drugs.

[Symptomatology and markers of the severity of erythematous drug eruptions]

OBJECTIVES

Skin reactions to drugs affect about 2.2 percent of inpatients. More often, they are described as morbilliform or maculopapular. The objectives of this study were to characterize these skin reactions and to look for severity markers.

METHODS

We retrospectively analyzed 133 cases of drug reactions collected in a Dermatology unit from 1973 to 1995 for whom, photographs and blood cell count were available. Well recognized disorders were excluded (Stevens-Johnson syndrome, Lyell syndrome, TEN, AGEP, vasculitis, phototoxicity, fixed drug eruption). Severity was defined on 3 criteria: hospitalization, skin reaction prolonged more than 21 days and visceral involvement. For each criteria, we studied the association with clinical and laboratory findings, first with univariate analysis, then with multivariate analysis for significant associations.

RESULTS

Characteristics of the 133 included cases were: women: 58 p. 100, mean age: 52 years, inpatients: 80 p. 100, mean interval from beginning of drug therapy to reaction: 12 days, mean duration: 26 days, responsible drugs: antibiotics: 41 p. 100, nonsteroidal antiinflammatory drugs: 11 p. 100, anticonvulsants: 10 p. 100. A few reactions showed a monomorphous pattern fitting a single denomination in a classic dermatological nomenclature: maculopapular: 10 p. 100, morbilliform: 6 p. 100, scarlatiniform: 5 p. 100, small papules: 5 p. 100. Polymorphous reactions were observed in 73 p. 100 of cases with 3 different patterns on the average. Nearly half of the cases exhibited maculopapular and scarlatiniform lesions simultaneously. We observed fever (61 p. 100), mucosal lesions (26 p. 100), lymphadenopathy (30 p. 100), eosinophilia (count > 500/mm3: 44 p. 100, > 1500/mm3: 17 p. 100), and visceral involvement (22 p. 100), including hepatitis (18 p. 100). Four severity markers were identified: fever, lymphadenopathy, erythema involving more than 60 p. 100 of the body surface area, eosinophilia.

CONCLUSION

This study underlines the polymorphous clinical presentation of skin reactions to drugs and the minority of maculopapular or morbilliform patterns leading us to propose the term of "erythematous drug reactions". Despite several biases (hospital recruitment of more severe reactions, retrospective analysis) this study is the first to show some severity markers. Close to the criteria used to define the "hypersensitivity syndrome" these simple clinical markers may have important practical implications.

Serious dermatologic reactions in children

Although serious reactions comprise only a small percentage of total adverse drug reactions, they are important in terms of morbidity and potential mortality. An update on serious dermatologic reactions in children is presented including serum sickness-like reactions due to cefaclor, hypersensitivity syndrome reactions (HSRs), and drug-induced pseudoporphyria. More detailed information on minocycline-induced reactions including drug-induced lupus and HSRs and lamotrigine-induced toxic epidermal necrolysis and Stevens-Johnson syndrome will be discussed.

Comprehensive hospital drug monitoring (CHDM): adverse skin reactions, a 20-year survey

Studies on the epidemiology of common adverse cutaneous drug reactions have rarely been reported, since they can only be successfully conducted in clinics of internal medicine employing consultant dermatologists and having a comprehensive or intensive system of monitoring. Between 1974 and 1993, the adverse skin reactions occurring in divisions of general internal medicine of three different hospitals were monitored by a computerized comprehensive system. The "drug-monitoring patient" was defined as the recipient of at least one drug during hospitalization. The relationship of the skin reactions to drug causality in these patients had to be either definite (proven by re-exposure) or probable (drug relation greater than that of nondrug causality). The skin reactions were classified into four diagnostic groups. Maculopapular exanthema, urticaria, and vasculitis were the three main groups. The fourth group comprised cases of nonhomogeneous but clinically well-defined special exanthema. For selected drugs and years of observation, special emphasis was placed on the study of time patterns (reaction time, exposure time). A total of 1317 definite or probable drug-induced skin reactions occurred during the hospitalization of 48,005 consecutively admitted "drug-monitoring patients": 1201 cases of maculopapular exanthema, 78 cases of urticaria, 18 cases of cutaneous vasculitis, and 20 cases of special exanthema (five of erythema multiforme minor, six of fixed eruption, one of photosensitivity reaction, and eight of acneiform eruption). The main drugs involved did not differ for the three main types of skin reactions, penicillins ranking in the first place, followed by sulfonamides--most often combined with trimethoprim--and in the third place nonsteroidal anti-inflammatory drugs. The reaction time (time from last drug exposure to first skin manifestation) for urticaria showed a relevant proportion of the acute type (within 1 h) and most of the subacute type (1-24 h). For maculopapular exanthema, the subacute or, rarely, the latent type (1-8 days, exceptionally more than 8 days) predominated. For aminopenicillins, the rate of occurrence of skin reactions increased with increasing exposure time up to 12 days, and then markedly diminished. Possibly due to the tendency to withdraw suspected drugs even in the case of minor (e.g., maculopapular) skin reactions, no severe events such as erythema multiforme major/Stevens-Johnson syndrome or toxic epidermal necrolysis occurred.

Epidemiology of drug-induced severe skin reactions

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe, sometimes life-threatening skin reactions that are often drug-induced. Unfortunately, the definitions and nomenclature of these severe skin reactions have been confusing, and thus various publications on this issue can hardly be compared. After several attempts have been made to clarify this situation, a consensus definition published in 1993 suggests the differentiation between erythema exsudativum multiforme majus (EEMM) and SJS, as well as an overlap group of SJS and TEN, whereas TEN with maculae is the most severe type of skin reaction with more than 30% of skin detachment related to the body surface area (BSA). This classification was applied to cases of severe skin reactions in several large studies that have been undertaken within the last few years and published recently. The incidence of SJS, SJS/TEN overlap and TEN has been estimated to be approximately 1.89 cases per one million people per year. Although SJS and TEN occur very rarely, a mortality rate of more than 40% can be calculated for patients suffering from TEN. One may conclude that mortality increases with age and the amount of skin detachment related to the BSA. A number of drugs have been reported to induce severe skin reactions, eg, anti-infective sulfonamides, antibiotics, anticonvulsants and nonsteroidal anti-inflammatory drugs. For risk evaluation for certain drugs or drug groups population-based data as ascertained by the German registry of severe skin reactions, and prescription data in defined daily doses can be used. In addition, risk evaluation is possible by performing a case-control study as it has been undertaken within different European countries. As long as the pathogenesis of drug-induced severe skin reactions is not known, and specific screening methods to identify susceptible individuals do not exist, the epidemiological approach will remain the only possibility for risk estimation.

Mechanisms of drug eruptions: Part I

The pathogenetic mechanisms underlying common, and less common but severe, adverse cutaneous drug reactions are reviewed. Pharmacogenetic variability may account for a susceptibility to serious drug reactions to sulphonamides and anticonvulsants, as well as to lupus erythematosus (LE)-like syndrome. Exanthematous drug reactions may have an immunological basis. Cell mediated cutaneous drug reactions, including lichenoid reactions, LE-like syndrome, fixed drug eruption, erythema multiforme, Stevens-Johnson syndrome and toxic epidermal necrolysis, will inevitably involve elements of the skin immune system. Graft-versus-host disease provides a useful model for aspects of these drug-induced disorders. Urticaria, angioedema, anaphylaxis and anaphylactoid reactions may involve Type I immunoglobulin (Ig)-mediated or Type III hypersensitivity, or may be caused by pharmacological, non-allergic means. Drug-induced vasculitis, serum sickness and the Arthus phenomenon are manifestations of the immune complex disease. Drug-induced pemphigus may involve immune dysregulation, but several thiol-containing drugs are able to cause antibody-independent acantholysis directly.

Clinical pattern of cutaneous drug eruption among children and adolescents in north India

Various types of cutaneous drug eruptions and the incriminating drugs were analyzed in 50 children and adolescents up to 18 years of age (34 or 65% boys, 16 or 32% girls). Thirteen (26%) patients had a maculopapular rash, 11 (22%) a fixed drug eruption (FDE), 10 erythema multiforme (EM), 6 (12%) toxic epidermal necrolysis (TEN), 5 (10%) Stevens-Johnson syndrome (SJS), 3 (6%) urticaria, and 2 (4%) erythroderma. The incubation period for maculopapular rashes, SJS and TEN due to commonly used antibiotics and sulfonamides was short, a few hours to two to three days, reflecting reexposure, and for drugs used sparingly such as antiepileptics and antituberculosis agents, was approximately one week or more, suggesting a first exposure. Antibiotics were responsible for cutaneous eruptions in 27 patients, followed by antiepileptics in 17, analgin in 4, and metronidazole and albendazole in 1 each. Cotrimoxazole, a combination of sulfamethoxazole and trimethoprim, was the most common antibacterial responsible for eruptions (11 patients), followed by penicillin and its semisynthetic derivatives (8 patients), sulfonamide alone (3 patients), and other antibiotics (4 patients). Antiepileptics were the most frequently incriminated drugs in EM, TEN, and SJS. The role of systemic corticosteroids in the management of SJS and TEN is controversial. We administered prednisolone or an equivalent corticosteroid 2 mg/kg/day for 7 to 14 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Drug hypersensitivity syndrome

Some types of hypersensitivity to drugs are defined either by the generic name of the drug or descriptive terms. They are sometimes assimilated to pseudolymphoma because the causative drugs are often the same, although the eruption lacks clinical and histopathological criteria of pseudolymphoma. It is then suggested to use 'idiosyncratic drug hypersensitivity syndrome' to define this type of drug reaction. As the skin and other organs may be involved, a generic name would help to determine a better definition and a surveillance program.

Cutaneous drug reactions

Cutaneous drug reactions are among the most common causes of skin eruptions in hospitalized patients. In outpatient clinics, drug eruptions represent a diagnostic and therapeutic challenge to the physician as any drug can cause an adverse cutaneous reaction. These reactions may be mediated by immunologic or nonimmunologic mechanisms. Cutaneous drug reactions may manifest themselves in various clinical morphologic patterns. Factors such as sun-exposure, concomitant drugs or diseases and host immune status can influence the type and morphology of lesions. History taking is one of the most important aspects in the evaluation of these patients and must be oriented so as to provide the information that will lead to the final diagnosis.

Drug eruptions

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Cutaneous drug reactions: pathogenesis and clinical classification

Cutaneous drug reactions may be classified with respect to pathogenesis and clinical morphology. They may be mediated by immunologic and nonimmunologic mechanisms. Immunologic reactions require host immune response and may result from IgE-dependent, immune complex-initiated, cytotoxic, or cellular immune mechanisms. Nonimmunologic reactions may result from nonimmunologic activation of effector pathways, overdosage, cumulative toxicity, side effects, ecologic disturbance, interactions between drugs, metabolic alterations, or exacerbation of preexisting dermatologic conditions. Certain defined, cutaneous, morphologic patterns are frequently associated with cutaneous drug reactions. These include urticaria, photosensitivity eruptions, erythema multiforme, disturbance of pigmentation, morbilliform reactions, fixed drug reactions, erythema nodosum, toxic epidermal necrolysis, lichenoid eruptions, and bullous reactions. In addition, certain drugs cause defined cutaneous syndromes. These include iodides and bromides, hydantoins, corticosteroids, antimalarial agents, gold, cancer chemotherapeutic agents, tetracyclines, thiazides and sulfonamides, nonsteroidal anti-inflammatory agents, and coumarin. The criteria for evaluation of possible drug reactions are presented and reviewed.

Drug eruptions

Although any drug may cause any dermatitis, it is possible to categorize a relatively few types of dermatitis and a relatively small number of drugs in such a way as to afford a practical approach to a sometimes confusing problem. These problems are generally clinical ones not requiring laboratory work and an experienced clinician will probably be able to manage most of these cases without extensive consultations.