From the Guidelines
Cat scratch disease lymphadenitis should be treated with azithromycin 500mg on day one followed by 250mg daily for 4 more days, as it has been shown to reduce lymph node size by 80% at 30 days in a double-blind placebo-controlled study 1. The disease is caused by Bartonella henselae, typically transmitted through cat scratches or bites, and can lead to regional lymph node enlargement, tenderness, and sometimes systemic symptoms like fever and malaise. Some key points to consider in the management of cat scratch disease lymphadenitis include:
- The disease course varies, but lymphadenopathy generally resolves within 1–6 months without treatment 1
- In about 10% of cases, the nodes suppurate, and needle aspiration may be required to relieve pain 1
- Extranodal disease (eg, central nervous system, liver, spleen, bone, and lung) develops in ≤2% of cases, and may require longer treatment courses or alternative antibiotics 1
- Supportive care includes warm compresses for painful lymph nodes and analgesics for pain relief
- Prevention involves proper cat handling, avoiding scratches and bites, and washing wounds promptly It is essential to note that diagnosis of Bartonella infections may be difficult because the organism is fastidious and difficult to grow in culture, and serological testing or PCR may be necessary to support the diagnosis 1.
From the Research
Cat Scratch Disease Lymphadenitis
- Cat scratch disease is a common infection that usually presents as tender lymphadenopathy, and it should be included in the differential diagnosis of fever of unknown origin and any lymphadenopathy syndrome 2.
- The disease is caused by the bacterium Bartonella henselae, which is transmitted to humans through cat scratches or bites, and the diagnosis is often made by obtaining a history of exposure to cats and a serologic test with high titers of immunoglobulin G antibody to B. henselae 2.
- Cat scratch disease is commonly diagnosed in children, but adults can also present with the disease, and the cardinal feature of the disease is a subacute regional granulomatous lymphadenitis 3.
- The disease can present with systemic symptoms such as low-grade fever and regional lymphadenopathy, and the most common sites of lymph node involvement are the axilla and the neck 3.
- Treatment for cat scratch disease is often not necessary, as most cases are self-limited, but antibiotics such as azithromycin may be used to speed recovery, and surgical procedures such as nodal excision may be necessary in severe cases 2, 3.
- Cat scratch disease can be mistaken for other conditions such as lymphoma due to its similar clinical presentation, and a thorough diagnostic approach is necessary to avoid misdiagnosis and mistreatment 4.
- Some studies have suggested that antibiotic therapy, such as gentamicin, may be effective in shortening the course of cat scratch disease, but more research is needed to confirm these results 5.
Diagnosis and Treatment
- Diagnosis of cat scratch disease is often made by obtaining a history of exposure to cats and a serologic test with high titers of immunoglobulin G antibody to B. henselae 2.
- Treatment for cat scratch disease is often not necessary, as most cases are self-limited, but antibiotics such as azithromycin may be used to speed recovery 2.
- Surgical procedures such as nodal excision may be necessary in severe cases of cat scratch disease 3.
- A thorough diagnostic approach is necessary to avoid misdiagnosis and mistreatment of cat scratch disease, as it can be mistaken for other conditions such as lymphoma 4.
Clinical Presentation
- Cat scratch disease can present with systemic symptoms such as low-grade fever and regional lymphadenopathy 3.
- The most common sites of lymph node involvement are the axilla and the neck 3.
- Cat scratch disease can present with a subacute regional granulomatous lymphadenitis, and it can be mistaken for other conditions such as lymphoma due to its similar clinical presentation 3, 4.