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Watch for clinical presentations of rat bite fever



Photo by: Linsenhejhej via Wikimedia Commons

Clinicians are being urged to consider rat bite fever (RBF) in children presenting with symptoms such as fever, arthralgias, and skin lesions, particularly when there is a history of contact with rats.


In an article published in the Dec. 2023 issue of The Chronicle of Skin & Allergy, Drs. Maryam Piram and Marc Lebel emphasized the importance of considering RBF in pediatric patients with rat bites, as the popularity of rats as pets has grown, influenced by their portrayal in films like "Ratatouille" and the "Harry Potter" series. They stressed that dermatologists may need to seek the input of infectious disease specialists for clinical evaluation of some dermatologic presentations.


Dr. Piram is a dermatologist at the CHU Ste-Justine and Associate Clinical Professor, Department of Pediatrics, University of Montreal, and Dr. Lebel is a pediatric infectious disease specialist at the CHU Ste-Justine and Associate Clinical Professor at the University of Montreal. They were speaking at the 21st annual pediatric dermatology update organized by the CHU Ste Justine and the University of Montreal.


RBF, caused by Streptobacillus moniliformis or Spirillum minus, can be fatal, with a mortality risk of up to 10% if untreated. Diagnosis involves culturing for the bacteria and consulting with an infectious disease specialist, with a cardiac examination to rule out endocarditis.


The condition, characterized by fever, vomiting, headache, muscle pain, joint swelling, and a rash that typically appears on the hands and feet, can be effectively treated with antibiotics if diagnosed early. However, the initial symptoms can be nonspecific, making early diagnosis crucial to prevent severe disease and death. The U.S. Centers for Disease Control advises that any signs of RBF after contact with rodents should prompt immediate medical attention.

“It [rat bite fever] still remains a relatively rare disease,” said Dr. Lebel. “The most important point will really be the questions for patients.”


Preventive measures against RBF include avoiding direct contact with rodents and maintaining good hygiene practices, such as washing hands thoroughly after handling rodents or their habitats. In the event of a bite or scratch, immediate wound cleaning and medical consultation are recommended to reduce the risk of infection.


with files from Chronicle Correspondent Louise Gagnon. Read a recent digital edition of The Chronicle of Skin & Allergy here. To apply for a complimentary* subscription or to receive a sample copy, please email health@chronicle.org with your contact information.


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