Cat-scratch Disease

Cat-scratch disease is an infection caused by Bartonella henselae, a pleomorphic Gram-negative bacillus. Patients develop lymphadenopathy and fever. It occurs worldwide annually; the pathogen is transmitted by contact with cats or cat scratches/bites. Typical features are primary skin lesion, lymphadenopathy, usually benign and self-limited. A few patients develop severe systemic disease such as granulomatous hepatitis, hepatosplenomegaly, neuritis, and meningoencephalitis. The course is 1-4 months.

Common Symptoms

Papulomacular rash; flu-like symptoms; mononeuritis multiplex; fatigue; paraplegia; diplopia; eschar

Causes and Pathogenesis

(1) Etiology: Wear et al. (1983) identified a pleomorphic Gram-negative bacillus. Brenner et al. (1991) named it Afipia felis, but later studies disproved this; Regnery et al. (1992) isolated Rochalimaea henselae from typical nodes; in 1993 Brenner merged Rochalimaea into Bartonella, giving B. henselae. It closely resembles B. quintane in morphology, culture, biochemistry, and cell-wall fatty acids; gltA has 65-66% homology with Rickettsia prowazekii, Coxiella burnetii, and E. coli; immunoblots show serological cross-reactivity. (2) Pathogenesis: The pathogen spreads lymphohematogenously causing multiorgan damage; mechanism is unclear but may involve delayed-type hypersensitivity to B. henselae components. With normal immunity, pathology is granulomatous/suppurative; with immunocompromise, it is vascular proliferative. Early electron microscopy shows pleomorphic Gram-negative organisms in vessel walls and macrophages, suggesting endothelial affinity. Node biopsy shows stellate necrotizing granulomas in the paracortex/follicles, progressing to microabscesses that coalesce, with epithelioid cells and occasional multinucleated giant cells; capsule thickens; fibroblasts form scars over weeks to months. Warthin-Starry silver stain detects the organism in lesions 1-4 weeks after onset.

Treatment

Traditional Chinese medicine, supportive therapy, drug therapy, surgical treatment

Preventive Measures

Do not keep or play with cats/dogs; after a cat scratch, disinfect immediately with iodine or mupirocin ointment and monitor regional nodes; patients generally do not need isolation.

Department to Visit

It is recommended to visit the Infectious Diseases department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.