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.