0521779407-C01 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:53
Cat Scratch Disease 287■disease usually follows bite or scratch of kitten or feral cat, most
commonly seen in children and young adults
■fleas important in transmission between cats; role of fleas in trans-
mission to humans unclearSigns & Symptoms
■A cutaneous papule or pustule develops at the site of animal contact
within 10 days of exposure
■The hallmark of CSD, regional lymphadenopathy without lymphan-
gitis, develops several weeks after the primary cutaneous lesion
■Single node involvement most common, but multiple nodes at single
or multiple sites can occur
■Suppuration occurs in a minority of cases
■Nonspecific systemic symptoms (low-grade fever, fatigue, malaise,
headache) may accompany adenopathy
■Less common manifestations include Parinaud’s oculoglandular
syndrome (granulomatous conjunctivitis with ipsilateral preauric-
ular lymphadenopathy), neuroretinitis (acute unilateral decrease in
visual acuity with papilledema and stellate macular infiltrates), gran-
ulomatous hepatitis and/or splenitis osteitis and encephalopathy
tests
■For classic CSD and Parinaud’s oculoglandular syndrome, diagnosis
made clinically and by exposure history
■For less common manifestations, diagnosis often made pathologi-
cally or serologically:
➣Neuroretinitis: single elevated antibody titer or four-fold rise in
titer to B. henselae confirms diagnosis
➣Granulomatous hepatitis/splenitis: abnormal liver function tests
prompt ultrasound or CT scan that demonstrates multiple
hypoechoic or hypodense lesions. Biopsy shows granulomas
with or without necrosis and stellate abscesses; silver stain may
reveal bacilli; serum serology positive
➣Osteitis: biopsy with granulomas as above, and serology positive
➣Encephalopathy: CSF nondiagnostic – may be normal or have
elevated protein and/or mild pleocytosis. Serum serologies pos-
itive.
differential diagnosis
■Other causes of lymphadenopathy – infectious mononucleosis,
CMV, toxoplasmosis, typical and atypical tuberculosis, syphilis, bru-
cella, fungal infections, malignancies, etc.