Multiple drug allergy syndrome: severe anaphylactic reaction due to topical rifamycin SV in a patient with hypersensitivity to ciprofloxacin

Antibiotic allergy

Although allergy to β-lactam and non-β-lactam antibiotics is commonly claimed, true allergy to these drugs is often absent. Reactions to antibiotics can be classified according to the interval between the last administration of the drug and the onset of symptoms, but except for immediate reactions occurring within an hour of exposure, which are almost always either IgE-mediated or due to direct stimulation of mast cells, reactions occurring later than 1 hour probably have multiple mechanisms, including being IgE-mediated or involving cell-mediated reactions. The latter are likely caused by drug-specific T lymphocytes. The diagnosis of antibiotic allergy can be difficult.

Antibiotic allergies in children and adults: from clinical symptoms to skin testing diagnosis

Hypersensitivity reactions to β-lactam and non-β-lactam antibiotics are commonly reported. They can be classified as immediate or nonimmediate according to the time interval between the last drug administration and their onset. Immediate reactions occur within 1 hour after the last drug administration and are manifested clinically by urticaria and/or angioedema, rhinitis, bronchospasm, and anaphylactic shock; they may be mediated by specific IgE-antibodies. Nonimmediate reactions occur more than 1 hour after the last drug administration. The most common manifestations are maculopapular exanthems; specific T lymphocytes may be involved in this type of manifestation. The diagnostic evaluation of hypersensitivity reactions to antibiotics is usually complex. The patient's history is fundamental; the allergic examination is based mainly on in vivo tests selected on the basis of the clinical features and the type of reaction, immediate or nonimmediate. Immediate reactions can be assessed by immediate-reading skin tests and, in selected cases, drug provocation tests. Nonimmediate reactions can be assessed by delayed-reading skin tests, patch tests, and drug provocation tests. However, skin tests have been well validated mainly for β-lactams but less for other classes of antibiotics.

Severe anaphylaxis caused by orally administered vancomycin to a patient with Clostridium difficile infection

We report the first case of anaphylaxis to oral vancomycin in a cystic fibrosis patient with severe and relapsing Clostridium difficile infection (CDI) refractory to metronidazole. The patient's colitis has been successfully treated with a combination of intravenous metronidazole and tigecycline.

Cutaneous adverse drug reactions to anti-tuberculosis drugs: state of the art and into the future

First- and second-line anti-tuberculosis drugs are associated with a diverse presentation of cutaneous adverse drug reactions (CADR), ranging from mild to life threatening. An individual drug can cause multiple types of CADR, and a specific type of CADR can be due to any anti-tuberculosis drug, which can make the management of tuberculosis (TB) following CADR challenging. The higher incidence of TB and CADR in HIV-infected persons makes TB-associated CADR a burgeoning problem for clinicians, particularly in high HIV-prevalence settings. This review discusses the pathogenesis, epidemiology, clinical presentation, diagnosis and management of TB-associated CADR. Clinical controversies including its impact on treatment outcomes, challenges in restarting optimal anti-tuberculosis therapy and the timing of highly active antiretroviral therapy initiation in those with HIV coinfection are also discussed. Finally, gaps in the current knowledge of TB-associated CADR have been identified and a research agenda has been proposed.

Allergic contact dermatitis to topical antibiotics: Epidemiology, responsible allergens, and management

Topical antibiotics are widely used to treat cutaneous, ocular, and otic infections. Allergic contact dermatitis to topical antibiotics is a rare but well-documented side effect, especially in at-risk populations. The purpose of this article is to review the epidemiology, responsible allergens, and management of allergic contact dermatitis to topical antibiotics.

LEARNING OBJECTIVE

After completing this learning activity, participants should be able to describe the epidemiology of allergic contact dermatitis related to topical antibiotics; show knowledge of the most common allergenic topical antibiotics; and understand the allergenic cross-reactivity pattern amongst topical antibiotics.

Distinct delayed T-cell response to beta-methasone and penicillin-G in the same patient

BACKGROUND

Multiple drug allergy syndrome is a clinical condition characterized by reactions against more than one different class of, both pharmacologically and structurally, unrelated drugs. Scanty data are available to date about a multiple drug delayed hypersensitivity syndrome. Our aim was to report the case of a delayed reaction to both beta-methasone (beta-MT) and penicillin-G (pen-G) occurring in the same patient, and analyse beta-MT- and pen-G-specific T-cell Lines (TCLs) with regard to their specificity, phenotype and cytokine profile.

METHODS

We generated two drug-specific TCLs from biopsies at the site of positive intradermal reactions, and analysed their immunophenotype, T-cell receptor Vbeta (TCR-Vbeta) domains expression and cytokine profile.

RESULTS

We demonstrated the specificity of the T cells isolated from positive intradermal test reactions to pen-G and beta-MT through the strict dose-dependent proliferation in response to drug-pulsed autologous antigen presenting cells. Fluorescence activated cell sorter (FACS) analysis revealed a predominance of CD4+ cells in the inflammatory cell infiltrate of intradermal test with beta-MT, while a predominance of CD8+ T cells in the site of delayed reaction to pen-G was found. The drug specific CD4+ and CD8+ T cells were heterogeneous, with regard to TCR-Vbeta usage. CD8+ pen-G-TCL displayed a preferential T helper 2 (Th2) profile, while a substantially heterogeneous pattern of cytokine production characterized specific beta-MT TCL.

CONCLUSION

The study describes the coexistence in the same patient of a delayed hypersensitivity to both penicillin G and beta-MT, driven, respectively, by pen-G-specificTh2-skewed CD8+ and beta-MT specificTh0 CD4+ T cells. This case further support the existence of a multiple drug allergy syndrome also for delayed hypersensitivity.