[1328] Clinical, Pathological and Immunohistological Study of Tularemic Skin Lesion and Lymphadenopathy

S Asano, M Kojima, F Shinya, H Fujita. Iwaki Kyoritsu General Hospital, Iwaki, Fukushima, Japan; Gunma Cancer Center Hospital, Ohta, Gunma, Japan; Ohara General Hospital, Fukushima, Japan

Background: Tularemia is an infectious disease caused Francisella tularensis-infected hare. It has been well known that hare-cooking persons suffered from regional lymphadenopathy. But, there were little reports concerning skin lesions in contrast to lymph node lesions. In this section, we show relationship between tularemic skin lesion and regional lymphadenopathy.
Design: Nineteen cases of finger skin lesions, two tonsills and fifty-four cases of lymph nodes of tularemia are clinico-pathologically studied by histology and immunohistology. We analyzed relationship between time-course and skin lesions or lymphadenopathy.
Results: (1).Serum antibody titer; It shows positivity at the first week and reaches the peak around the third week. The positive reaction persists till the twentieth week after infection. (2).Skin; Inflammatory cells and small necrotic focus appear in the subcutaneous site till the second week after infection. Through the second to the sixth week, it appears ulcers and there are a lot of antigen presenting cells such as lymphocytes and dendritic cells in dilated lymph vessels in dermis. There are many small epithelioid granulomas with central necrosis in dermis as detected in subcutaneous. After the sixth week, inflammatory cells increase and it appears irregular shaped fused granulomas with central homogenous lesions in subcutaneous. (3). Lymph node; It appears primitive abscess surrounded by rough arranged mononuclear cells and histiocytic cells till the second week after infection. Many small epithelioid granulomas with central necrosis and aggregation of CD20+ lymphocytes contacted with granulomas are detected through the lymph node till the sixth week. CD4+ lymphocytes are richer than CD8+ cells through granulomas. After the sixth week, there appear granulomas with central caseous necrosis like lesions and aggregation of CD20+ lymphocytes as early phase.
Conclusions: The bacteria enter from the finger skin immediately after contact to the infected hare and it makes abscess forming granulomatous lesion in skin and regional lymph nodes. It may conclude that regional lymph node is draining from the involved cutaneous sites via lymph vessel and the antibody production period coincide with aggregation of CD20+ lymphocytes in lymph nodes. In addition, tularemic lymphadenopathy is a subacute type of dermatopathic lymphadenopathy.
Category: Infections

Monday, March 9, 2009 1:00 PM

Poster Session II # 191, Monday Afternoon