Physiopathology and treatment of severe drug eruptions

A New-Onset Rash in the Setting of Rifaximin Treatment for Hepatic Encephalopathy

We present one of the first cases in the literature to describe an association between Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) and rifaximin treatment in a patient with a recent diagnosis of alcoholic hepatitis, stage 2 hepatic encephalopathy, and no known existing allergies. Although SJS/TEN may be a rare reaction with rifaximin, it should be an important clinical consideration.

Amlodipine-induced toxic epidermal necrolysis

The objective of this study is to report a case of amlodipine-induced dermatotoxicity following treatment for diabetic nephropathy. Although other members of the dihydropyridine calcium channel blockers have been reported to cause dermatotoxic reactions, this is the first report attributing this effect to amlodipine. A 71-year-old diabetic and hypertensive woman had been noted to have worsened renal dysfunction and hyperkalemia attributed to enalapril, thus a trial of amlodipine was begun. On day 12 of amlodipine therapy, the patient developed a pruritic maculopapular rash on her hands for which she sought medical attention. On day 16, she presented again to the emergency department now with hives and small blisters involving the trunk and arms with ∼25% TBSA involvement warranting transfer to a regional burn treatment center. The rash progressed after admission to 48.5% TBSA and included conjunctival sloughing. The patient's hospital course was uneventful, and she was discharged after 8 days. Drug-induced dermatotoxicity presenting as toxic epidermal necrolysis is often caused by antibiotics and antiepileptic medications; however, calcium channel blockers are an uncommon cause. The Naranjo assessment yielded a score of 5, and the SCORTEN was 4 with a predicted mortality of 58%. This report represents the first published case of amlodipine-induced toxic epidermal necrolysis.

Danger signs in drug hypersensitivity

ADRs are frequently considered iatrogenic complications and, therefore, pose a specific challenge for the physician-patient relationship. Early recognition of a potential ADR is possible, especially on the skin, in addition to characteristic clinical danger signs. Cutaneous manifestations are variable, depending on the causative pathomechanism. It is impossible to conclude the causative agent from the morphology of the cutaneous lesions. The intake of several drugs in the time before the elicitation of the drug reaction usually poses a diagnostic challenge. It is crucial for the precision of any further allergological work-up to document the type of rash precisely as well as the time course of drug intake and appearance of the first symptoms. involvement of internal organs or circulating blood cells. Timely recognition of such cutaneous lesions and the correct differential diagnosis with prompt withdrawal of the putative culprit drug are essential to reducing morbidity and preventing mortality. This article discusses risk factors, early symptoms, and danger signs indicating a possibly severe course of an ADR and advises on early actions.

New insights in toxic epidermal necrolysis (Lyell's syndrome): clinical considerations, pathobiology and targeted treatments revisited

Drug-induced toxic epidermal necrolysis (TEN), also known as Lyell's syndrome, is a life-threatening drug reaction characterized by extensive destruction of the epidermis and mucosal epithelia. The eyes are typically involved in TEN. At present, the disease has a high mortality rate. Conceptually, TEN and the Stevens-Johnson syndrome are closely related, although their severity and outcome are different. Distinguishing TEN from severe forms of erythema multiforme relies on consideration of aetiological, clinical and histological characteristics. The current understanding of the pathomechanism of TEN suggests that keratinocytes are key initiator cells. It is probable that the combined deleterious effects on keratinocytes of both the cytokine tumour necrosis factor (TNF)-alpha and oxidative stress induce a combination of apoptotic and necrotic events. As yet, there is no evidence indicating the superiority of monotherapy with corticosteroids, ciclosporin (cyclosporine) or intravenous immunoglobulins over supportive care only for patients with TEN. However, the current theory of TEN pathogenesis supports the administration of a combination of antiapoptotic/antinecrotic drugs (e.g. anti-TNF-alpha antibodies plus N-acetylcysteine) targeting different levels of the keratinocyte failure machinery.

Drug rash with eosinophilia and systemic symptoms syndrome: sex and the causative agent

The study was conducted to determine whether there is a sex difference in the causative agent of drug rash with eosinophilia and systemic symptoms (DRESS) syndrome. A retrospective review of hospital records from 1999 to 2006 in the dermatology department of a large municipal medical center found 8 patients who met the criteria for DRESS syndrome: drug-induced generalized eruption, associated systemic involvement (lymph node or visceral), and presence of eosinophilia (eosinophil count > or =1500/microL and/or circulating atypical lymphocytes). There were 4 men and 4 women, aged 19 to 53 years, with a mean age of 38 years. A sex difference was found in 3 parameters: (1) age, younger age in women; (2) time interval between drug intake and rash, shorter in women; and (3) the culprit drug: carbamazepine in 2 men and 2 women, salazopyrin in 2 women, and phenytoin in 2 men. While the sample is small, there is an indication of sex differences in the DRESS syndrome.

Recognition and Management of Severe Cutaneous Drug Reactions

Cutaneous drug reactions are among the most common types of adverse drug reactions. This article focuses on the recognition and management of severe cutaneous drug eruptions, including the drug-hypersensitivity syndrome, serum sickness-like reaction, acute generalized exanthematous pustulosis, Stevens-Johnson syndrome, and toxic epidermal necrolysis. Cutaneous reactions are considered severe when they can result in serious skin damage or involve multiple organs. Some of these reactions can cause significant morbidity or death. Each may be confounded by diagnostic difficulties, confusion in ascertaining causality, and treatment challenges.

Colonic involvement in Stevens-Johnson syndrome

Severe gastrointestinal tract involvement is a rare manifestation of Stevens-Johnson syndrome (SJS). The case is described of a 17 year old man who developed SJS secondary to phenytoin. In addition to the cutaneous, ocular, and oral mucosal lesions typical of SJS, he also developed persistent, bloody diarrhoea associated with life threatening malnutrition. Serial colonoscopy showed severe and progressive colitis. He was treated with a combination of long term nutritional support, probiotic therapy, and supportive measures. He was eventually discharged from hospital six months after admission when the diarrhoea improved and he began to gain weight.

Symptoms and danger signs in acute drug hypersensitivity

Early and rapid recognition of severe adverse drug reactions is essential. Prompt withdrawal of the offending drug is the most important action to minimize morbidity and mortality. Dependent on the type of reaction, e.g. in immediate type reactions instant withdrawal and therapy are mandatory, whereas in delayed reactions diagnosis as early as possible may be life-saving. The skin is an important herald organ and may early signal a severe evolution of a cutaneous reaction or involvement of circulating blood cells or internal organs. A synthesis considering all factors should be made to obtain an early and correct diagnosis.

Lamotrigine-induced rash--worth a rechallenge

OBJECTIVES

The only serious adverse event associated with lamotrigine (LTG) treatment is a hypersensitivity reaction primarily presenting as a rash. Despite this concern, LTG is an antiepileptic drug (AED) with one of the most favorable efficacy/tolerability ratio compared with the new as well as the old AEDs. Thus, this study aimed to evaluate the results of rechallenge with LTG after the initial rash.

MATERIAL AND METHODS

A total of 688 patients (350 as monotherapy, and 338 as add-on therapy) with either idiopathic generalized epilepsy or focal epilepsy were treated with LTG. The patients with LTG-induced rash were rechallenged to LTG. The dosage schedule was: 5 mg every day or every second day for 14 days, increased by 5 mg every 14th day to 25 mg a day. After achieving the daily dosage of 25 mg/day, the up-titration was completed following the current guidelines.

RESULTS

A total of 52 patients developed a rash. The LTG-induced rash occurred in 6%, where 12 (1.8%) developed a rash shown to be coincidentally associated with the initiation of LTG therapy. In their cases LTG was continued with success without intermission. Nineteen (38%) of the initial cohort were rechallenged with LTG, with a success rate of 84%.

CONCLUSION

This study is the first one to provide a successful recipe verified in time for the rechallenge with LTG after the initial drug-induced rash. Importantly, the concurrent use of valproate (VPA) was not found in this study to represent an additional risk factor for the occurrence of the rash during rechallenge with LTG. Our results agree with previous findings that women are more likely to develop the rash (P < 0.009).

Treatment of toxic epidermal necrolysis with moisture-retentive ointment: a case report and review of the literature

Toxic epidermal necrolysis (TEN) is a rare condition that was described by Lyell in 1956. It is a severe, acute, adverse, primarily drug-induced, potentially fatal, cutaneous reaction that is characterized by large areas of skin desquamation and sloughing, similar in many aspects to second-degree burns. The treatment of cutaneous drug reactions rests essentially on immediate diagnosis and recognition of the disease process, accurate history, thorough physical examination, prompt discontinuation of the offending drug, and supportive care. TEN patients are best managed in specialized burn units. Nevertheless, the management remains very much individualized, based on the clinical setting. Topical wound care remains an essential factor in the treatment of burn-like syndromes and is a main determining parameter for morbidity and mortality. As the value of moist environment in wound healing is being fully appreciated, we report on the use of a newly introduced ointment, the Moist Exposed Burn Ointment (Julphar; Gulf Pharmaceutical industries, Ras El-Khaymah, United Arab of Emirutes), a moisture-retentive ointment, in the successful management of a case of TEN.

10. Drug allergy

Adverse drug reactions are common, but only 6% to 10% are immunologically mediated. Unlike most adverse drug reactions, allergic drug reactions are unpredictable. Whereas some drug-induced allergic reactions may be easily classified into one of the four Gell and Coombs hypersensitivity categories, many others that appear to have an immunologic component cannot be classified because of our lack of mechanistic information. Theoretically, any drug can induce an immune response. However, some drugs are more likely to elicit clinically relevant immune responses than are others. Drugs in this category include antimicrobial drugs, anticonvulsants, chemotherapeutic agents, heparin, insulin, protamine, and biologic response modifiers. After a drug-disease connection is established, it must be determined whether the reaction was immunologically mediated. Subsequently, confirmatory tests, if available, should be used to determine the allergic status of the patient. If these tests are not available, a graded challenge or desensitization may be considered, depending on the type of clinical reaction previously demonstrated and the need for drug readministration. Education of the patient and primary care physician is an important component of patient management.