Amoxicillin-associated linear IgA bullous dermatosis

Linear IGA bullous dermatosis potentially triggered by vaccination

Linear IgA bullous dermatosis (LABD) is a mucocutaneous autoimmune blistering disease affecting both adults and children. It is caused by IgA antibodies targeting multiple antigens along the basement membrane zone, leading to disruption of dermoepidermal junction and development of bullous lesions which often presents in characteristic arrangement. Although most LABD cases have been reported to be idiopathic, different triggers have been described, including several drugs and infection. However, the occurrence of vaccine-induced cases of LABD is not widely known and accepted due to the few reports available. We present two cases of LABD occurred following different triggers, rising the suspicion for a possible pathogenetic role of vaccines.

Case Report: Linear IgA Bullous Dermatosis Triggered by Amoxicillin-clavulanic acid

Linear IgA bullous dermatosis (LABD) is rare autoimmune disease that can be caused with or without drugs. We present a 32 year old male with LABD secondary to Amoxicillin-clavulanic acid with complete recovery after the antibiotic was discontinued. Keywords: Linear IgA Bullous disease, Vancomycin, Amoxicillin-clavulanic acid

Old dog begging for new tricks: current practices and future directions in the diagnosis of delayed antimicrobial hypersensitivity

PURPOSE OF REVIEW

Antimicrobials are a leading cause of severe T cell-mediated adverse drug reactions (ADRs). The purpose of this review is to address the current understanding of antimicrobial cross-reactivity and the ready availability of and evidence for in-vitro, in-vivo, and ex-vivo diagnostics for T cell-mediated ADRs.

RECENT FINDINGS

Recent literature has evaluated the efficacy of traditional antibiotic allergy management, including patch testing, skin prick testing, intradermal testing, and oral challenge. Although patch and intradermal testing are specific for the diagnosis of immune-mediated ADRs, they suffer from drug-specific limitations in sensitivity. The use of ex-vivo diagnostics, especially enzyme-linked immunospot, has been highlighted as a promising new approach to assigning causality. Knowledge of true rates of antimicrobial cross-reactivity aids empirical antibiotic choice in the setting of previous immune-mediated ADRs.

SUMMARY

In an era of increasing antimicrobial resistance and use of broad-spectrum antimicrobial therapy, ensuring patients are assigned the correct 'allergy label' is essential. Re-exposure to implicated antimicrobials, especially in the setting of severe adverse cutaneous reaction, is associated with significant morbidity and mortality. The process through which an antibiotic label gets assigned, acted on and maintained is still imprecise. Predicting T cell-mediated ADRs via personalized approaches, including human leukocyte antigen-typing, may pave future pathways to safer antimicrobial prescribing guidelines.

Autoimmune bullous diseases associations

The presence of one autoimmune disorder helps lead to the discovery of other autoimmune conditions. It is thought that diseases in which autoimmunity is a feature tend to be associated together more often than one can ascribe to chance. A variety of diseases have been implicated in the onset of intraepidermal and subepidermal autoimmune diseases. The presence of one autoimmune disease should alert the physician to watch for a second immunologic disorder. A list of autoimmune bullous diseases associations includes autoimmune bullous diseases, pemphigus, pemphigoid, epidermolysis bullosa acquisita, dermatitis herpetiformis (Duhring), linear immunoglobulin A disease, and multiple autoimmune syndrome.

Bullous skin eruption in an HIV patient during antiretroviral drugs therapy

Dermo-epidermal blistering is an uncommon presentation of adverse drug reactions. Several drugs are associated to such eruptions, but review of current knowledge does not list antiretroviral drugs. A 37-year-old Caucasian HIV-positive woman presented with a 6-week history of diffuse annular blistering affecting the trunk and limbs. Lesions appeared both on erythematous and normal-appearing skin. The patient was in treatment with antiretroviral (lamivudine + didanosine + nelfinavir) for 2 years. A history of previous adverse reactions to betalactams, nonsteroidal anti-inflammatory drugs, and a nevirapine-induced hepatitis was also referred. Histopathology showed a dermo-epidermal blister; direct immunofluorescence was positive for IgG, C3c at the basement membrane zone; enzyme-linked immunosorbent assay was positive for BP180 antigen. Oral prednisone 1 mg/kg daily for 20 days led to poor improvement. Discontinuation of the antiretrovirals was followed by a rapid healing. Blisters reappeared at first re-introduction essay 1 month later. Awareness of iatrogenic dermo-epidermal blistering is necessary to suspect the diagnosis and avoid long-term immunosuppressant treatment. Complete spontaneous recovery after withdrawal of the responsible drug and relapse at rechallenge are the main criteria for the diagnosis. Factors related to the state of the HIV infection, and/or immunodeficiency may have contributed in precipitating the reaction in the present authors' case.