A retrospective histological and immunohistochemical study has been carried out in 25 cases of tick bites recorded in our Departments. The samples that included an attached tick showed a cement cone anchoring the mouthparts to the skin and a blood-soaked, spongiform appearance of the superficial dermis, with a mild neutrophilic and eosinophilic infiltration. The vessels displayed a loose multilayered endothelial proliferation, with plump endothelia, permeated with erythrocytes. A few of them were severed, allowing copious blood extravasation. The established lesions included the following: erythema chronicum migrans-like cases, foreign body granulomas-sometimes containing remnants of the mouthparts-cutaneous lymphoid hyperplasia, either of the T-cell or the B-cell type, and tick-bite alopecia. In both the T-cell and B-cell pseudolymphomas, several vessels showed concentric endothelial and perithelial proliferation similar to that seen in the acute lesions. In the tick-bite alopecia, a lymphocytic infiltrate attacked the permanent portion of the hair follicles, whose reaction was a noticeable hyperplasia of the fibrous sheaths, although only a minority of the hairs was destroyed. The observed alterations are specific in the acute lesions and in the alopecia, where they directly arise as a result of the interactions between the host's tissues and the antihemostatic, anti-inflammatory, and immunomodulatory chemicals contained in the tick saliva. In the other lesions, the changes seem less characteristic, although the fragments of mouthparts and the special vascular changes provide a clue to their etiology.
|Data di pubblicazione:||2008|
|Titolo:||LOCAL REACTIONS TO TICK BITES|
|Autori:||CASTELLI E; CAPUTO V; MORELLO V; TOMASINO RM|
|Tipologia:||Articolo su rivista|
|Citazione:||CASTELLI E, CAPUTO V, MORELLO V, & TOMASINO RM (2008). LOCAL REACTIONS TO TICK BITES. AMERICAN JOURNAL OF DERMATOPATHOLOGY, 30, 241-248.|
|Digital Object Identifier (DOI):||10.1097/DAD.0b013e3181676b60|
|Appare nelle tipologie:||01 - Articolo su rivista|