Tularemia-induced erythema multiforme minor in an 11-year-old girl

Genetic Determinants of Antibiotic Resistance in Francisella

Tularemia, caused by Francisella tularensis, is endemic to the northern hemisphere. This zoonotic organism has historically been developed into a biological weapon. For this Tier 1, Category A select agent, it is important to expand our understanding of its mechanisms of antibiotic resistance (AMR). Francisella is unlike many Gram-negative organisms in that it does not have significant plasmid mobility, and does not express AMR mechanisms on plasmids; thus plasmid-mediated resistance does not occur naturally. It is possible to artificially introduce plasmids with AMR markers for cloning and gene expression purposes. In this review, we survey both the experimental research on AMR in Francisella and bioinformatic databases which contain genomic and proteomic data. We explore both the genetic determinants of intrinsic AMR and naturally acquired or engineered antimicrobial resistance as well as phenotypic resistance in Francisella. Herein we survey resistance to beta-lactams, monobactams, carbapenems, aminoglycosides, tetracycline, polymyxins, macrolides, rifampin, fosmidomycin, and fluoroquinolones. We also highlight research about the phenotypic AMR difference between planktonic and biofilm Francisella. We discuss newly developed methods of testing antibiotics against Francisella which involve the intracellular nature of Francisella infection and may better reflect the eventual clinical outcomes for new antibiotic compounds. Understanding the genetically encoded determinants of AMR in Francisella is key to optimizing the treatment of patients and potentially developing new antimicrobials for this dangerous intracellular pathogen.

Triggers, clinical manifestations, and management of pediatric erythema multiforme: A systematic review

BACKGROUND

Erythema multiforme (EM) is an acute inflammatory mucocutaneous condition. EM is rarely described in children and infants.

OBJECTIVE

To investigate the triggers, clinical manifestations, and treatment of pediatric EM.

METHODS

Systematic literature review of pediatric EM.

RESULTS

After full-text article review, we included 113 articles, representing 580 patients. The mean age was 5.6 years, ranging 0.1-17 years. Infectious agents were the main triggers: herpes simplex virus (HSV) in 104 patients (17.9%) and Mycoplasma pneumoniae in 91 patients (15.7%). In total, 140 cases (24.1%) were drug-related and 89 cases (15.3%) had other triggers, such as vaccines (19 patients, 3.2%). In total, 229 patients had EM major (39.5%). Treatment was supportive care only (180 patients, 31.1%), systemic corticosteroids (115 patients, 19.8%), antivirals (85 patients, 14.6%), and antibiotics (66 patients, 11.3%), mostly macrolides (45 patients, 7.7%). Long-term sequelae were rare (1.3%). Pediatric EM was reported in 19 infants (3.2%). The main trigger was vaccination (9 patients). Infantile EM was EM major in 2 cases and EM minor in 17. Infants were less prone to develop EM major than older children (P < .01). Pediatric EM was recurrent in 83 cases (14.3%), which was triggered by HSV in 36 patients (61%). Recurrence affected older children.

LIMITATIONS

Potential confusion between Steven Johnson syndrome and EM major in addition to publication bias.

CONCLUSION

Pediatric EM is a rare disease, mainly triggered by infections. This condition can affect all mucosal surfaces, most commonly the oral mucosae. The diagnosis is clinical, and management relies on supportive care. Vaccines are a particular trigger in infants. Recurrent cases are most commonly linked to HSV. Dermatologists and pediatricians should be aware of this potentially recurrent and severe condition.