[Verapamil-induced linear IgA disease mimicking toxic epidermal necrolysis]

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

AIMS

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

METHODS

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

RESULTS

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 Among them, enoxaparin, minocycline and vibramycin were previously unpublished. For all patients, the suspect drug was withdrawn; 15 did not receive any treatment.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

CONCLUSIONS

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

Current Perspectives on Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are considered a delayed-type hypersensitivity reaction to drugs. They represent true medical emergencies and an early recognition and appropriate management is decisive for the survival. SJS/TEN manifest with an "influenza-like" prodromal phase (malaise, fever), followed by painful cutaneous and mucous membrane (ocular, oral, and genital) lesions, and other systemic symptoms. The difference between SJS, SJS/TEN overlap, and TEN is defined by the degree of skin detachment: SJS is defined as skin involvement of < 10%, TEN is defined as skin involvement of > 30%, and SJS/TEN overlap as 10-30% skin involvement. The diagnosis of different degrees of epidermal necrolysis is based on the clinical assessment in conjunction with the corresponding histopathology. The mortality rates for SJS and TEN have decreased in the last decades. Today, the severity-of-illness score for toxic epidermal necrolysis (SCORTEN) is available for SJS/TEN severity assessment. Drugs with a high risk of causing SJS/TEN are anti-infective sulfonamides, anti-epileptic drugs, non-steroidal anti-inflammatory drugs of the oxicam type, allopurinol, nevirapine, and chlormezanone. Besides conventional drugs, herbal remedies and new biologicals should be considered as causative agents. The increased risk of hypersensitivity reactions to certain drugs may be linked to specific HLA antigens. Our understanding of the pathogenesis of SJS/TEN has improved: drug-specific T cell-mediated cytotoxicity, genetic linkage with HLA- and non-HLA-genes, TCR restriction, and cytotoxicity mechanisms were clarified. However, many factors contributing to epidermal necrolysis still have to be identified, especially in virus-induced and autoimmune forms of epidermal necrolysis not related to drugs. In SJS/TEN, the most common complications are ocular, cutaneous, or renal. Nasopharyngeal, esophageal, and genital mucosal involvement with blisters, erosions as well as secondary development of strictures also play a role. However, in the acute phase, septicemia is a leading cause of morbidity and fatality. Pulmonary and hepatic involvement is frequent. The acute management of SJS/TEN requires a multidisciplinary approach. Immediate withdrawal of potentially causative drugs is mandatory. Prompt referral to an appropriate medical center for specific supportive treatment is of utmost importance. The most frequently used treatments for SJS/TEN are systemic corticosteroids, immunoglobulins, and cyclosporine A.

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

BACKGROUND

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

OBJECTIVES

To compare the clinical and histological forms of LABD.

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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