Pupura Hemorrhagica

Purpura hemorrhagica is an aseptic necrotizing vasculitis primarily linked to S. equi infection or antigens

Purpura hemorrhagica is an aseptic necrotizing vasculitis primarily linked to S. equi infection or antigens. Its origin, largely undisclosed, might emerge 2 to 4 weeks post-bacterial infections (Streptococcus equi equi, S. zooepidemicus) or other triggers like drugs, infections, or neoplasia. "Bastard strangles" denotes abnormal Streptococcus equi subsp. equi abscess formation across diverse sites.

Immunological Insights into Purpura Haemorrhagica

Platelet count remains within reference range, distinct from DIC. Streptococcus equi infection sparks immune complex deposition in small vessels, activating complement, increasing vascular permeability, and inciting edema, hemorrhage, ischemia, and necrosis. Rooted in type-III hypersensitivity, it arises from antigen-antibody complex accumulation, triggering affliction.

Its pathogenesis involves immune complex deposition within vessel walls. Roughly 50% cases remain idiopathic.

Clinical signs span from mild to fatal, encompassing fever, depression, edema, petechiae, ecchymoses, limb edema, serous exudation, possible necrosis, ulceration, mucous membrane ecchymoses and the potential to impact the gastrointestinal tract, lungs, and muscles. Systemic symptoms include anorexia, pyrexia, and tachycardia.

Diagnosis leans on history, clinical signs, and biopsies revealing neutrophilic infiltrates surrounding small vessels. Diagnosis relies on distinct clinical signs, supported by skin biopsies for histopathology, involves histological identification of leukocytoclastic vasculitis, S. equi isolation, and elevated IgA/IgG titers. Thrombocytopenia is typically absent.

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