Cat scratch fever misdiagnosed as schizophrenia

by Michael Broad · March 23, 2020

A Bartonella infection (cat scratch fever infection) can mimic mental illness. Doctors should be aware of this. Observing stretch marks in the skin may be a telling symptom.

Stretch marks caused by cat scratch disease. This symtom is important in making a correct diagnosis.

A case reported online from America provides insights into how cat scratch fever caused by the bacteria Bartonella henselae can produce symptoms which can look like the person has schizophrenia. The mental health issues can cause misdiagnosis.

The gentside.com website reports on the case of a healthy boy aged 14 who developed symptoms of confusion, depression and aggressive behaviour. He had psychotic episodes. He developed suicidal thoughts. He also believed that his two cats and a dog (his companion animals) would kill him.

The boy was an good student. The surprising symptoms resulted in an initial diagnosis of schizophrenia. But after psychotic drug treatments with little benefit, seven months later another doctor diagnosed cat scratch fever caused by Bartonella henselae, a bacteria deposited under the skin by a cat when they scratch the person. The boy suffered for months with painful treatments and hospitalisation.

It took a lot of time to come to the correct diagnosis and an extraordinary amount of money: $400,000 US.

One aspect of the correct diagnosis seems important: there were lesions along the boy’s thighs and armpits resembling stretch marks. Lesions on the skin are associated with a Bartonella henselae infection.

Bacteria. Bartonella henselae. Picture in public domain.

The Science Daily website lists a study of March 2019 which is titled: Bartonella and sudden-onset adolescent schizophrenia. The adolescent in the study was misdiagnosed with schizophrenia when he had a Bartonella henselae infection (associated with cat scratch fever, also called cat scratch disease).

If there is a moral to the story it is for adolescent boys to be gentle and respectful when interacting with the family cat. There is no suggestion that the boy in question was not careful. However, gentleness and an awareness of feline behaviour and how they react to handling can help avoid a careless scratch which can occur in play.

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