cat scratch disease

introduction

cat scratch fever or cat scratch disease is caused by a bacteria Bartonella henselae present in the saliva of some cats which enters the human via a scratch, or on the open eye - in which case a granulomatous conjunctivitis with preauricular LNs (Parinaud's syndrome) may occur.
it is a common cause of chronic swollen lymph nodes in children, and most cases occur in children or adolescents presumably as they have the most contact with cats
the usual 1st clue is the tender regional lymphadenopathy which usually occurs 2-3 weeks later and there may be a small papule at the scratch site
they may have constitutional symptoms of fever, malaise, fatigue, headache, loss of appetite, sore throat, weight loss
splenomegaly may be found
the Bartonella henselae IFA serology test is highly accurate for identifying infection caused by this bacteria
Rx is usually with azithromycin (particularly in patients with AIDS when the infection is more serious) although most cases are self-limiting after some months
in immunocompromised people, there is a risk of complications such as encephalitis, neuroretinitis, and osteomyelitis