Cat scratch disease is an infection transmitted by cat scratches and bites. The lesion is usually small and less than 1 cm in length. It is normally a benign, self-limiting illness lasting for about 6-12 weeks. It is caused by an exposure to bartonella henselae bacteria.
Scratches or bites from an infected cat can cause symptoms in people including swollen and draining lymph nodes, fever, fatigue and headache. Swollen, tender, or hard lymph nodes could be confused with a soft tissue tumor.
Regional Lymphadenopathy (main clinical feature)
These areas of lymph node concentration include cervical nodes, axillary nodes, cubital (epitrochlear nodes), and inguinal nodes.
Timeline of events
The timeline of events leading to cat scratch disease first begins with a bite or scratch. Within one week, there is the development of a skin lesion in about 50% of the patients. There will be noticeably enlarged lymph nodes within the first two weeks.
Swollen lymph nodes with no other etiology and a scratch or bite from being in contact with a cat, could suggest the presence of cat scratch disease. Symptoms are self-limiting and can vary from mild to severe, lasting for several weeks.
The physician should check for elevated sedimentation rate and C-Reactive protein (CRP), both are blood tests that could show infection. A positive skin test for cat-scratch disease is important for establishing the diagnosis.
Treatment includes doxycycline, ciprofloxacin and azithromycin. It is a pseudotumor and should be considered in the differential diagnosis of soft tissue lesions. No biopsy is necessary. A biopsy will show lymphoid tissue and necrotizing granulomas.
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