Dissemination in cutaneous leishmaniasis. 3. Lymph node involvement.

Area of Science:

• Medical Microbiology
• Infectious Diseases
• Dermatology

Background:

• Zoonotic cutaneous leishmaniasis (CL) is a significant public health concern in endemic regions.
• Understanding the full spectrum of CL manifestations, including systemic involvement, is crucial for effective management.
• Lymph node involvement in CL has been reported but requires further characterization.

Purpose of the Study:

• To investigate the prevalence and characteristics of lymph node enlargement in patients with zoonotic cutaneous leishmaniasis (CL) caused by Leishmania major.
• To determine the pathological and immunopathological basis of lymphadenitis in CL patients.
• To explore the role of leishmanial antigen dissemination in lymph node involvement.

Main Methods:

• A study was conducted on 643 patients with CL in an endemic focus in Saudi Arabia.
• Clinical examination recorded lymph node enlargement, location, and characteristics.
• Pathologic and immunopathologic studies were performed on lymph node biopsies.

Main Results:

• Lymph node enlargement was observed in 10.26% of patients (66 out of 643).
• Epitrochlear lymph nodes were most commonly affected (68%), followed by inguinal (18%), axillary (15%), and cervical (11%).
• Leishmanial antigen was detected in all eight biopsied lymph nodes, while amastigotes were found in only two.

Conclusions:

• Lymph node enlargement is a notable manifestation of Leishmania major infection, indicating dissemination.
• Leishmanial antigen dissemination, rather than parasitic presence, may be responsible for lymphadenitis in some CL cases.
• Further research is warranted to understand the immunopathogenesis of leishmanial lymphadenitis.