Púrpura = hemorragia visível na pele e/ou mucosas
Mecanismo
- Multifocal extravasation of blood into the skin or mucous membranes
Apresentação clínica
- Morphology
- Brownish-red or purple macules, papules or plaques
- O plano macroscópico reflete o mecanismo microscópico
- Macular
- Non-palpable, non-blanchable
- Extravasamento passivo de eritrócitos, sem lesão inflamatória significativa da parede vascular
- Petechiae (<4mm)
- Superficial, pinhead-sized, round, hemorrhagic macules; initially bright red/rust color Idiopathic Thrombocytopenic Purpura (ITP)Thrombotic Thrombocytopenic Purpura
- Intermediate (5-9mm)
- Ecchymoses (≥1cm)
- “Bruises” deeper and more extensive interstitial hemorrhage, bluish or yellowish (as it resolves)
- Purpura
- Palpable, partially blanchable
- Implicam inflamação vascular dos pequenos vasos (púrpura palpável) e/ou oclusão vascular dos médios vasos da derme (púrpura retiforme)
- Palpable:
- Inflammatory purpura with early erythema
- red-brown-violaceous papules or plaques
- Retiform: purpura distinct subtype → marker of thrombotic or occlusive microvascular disease
- Hemorrhage around the dermal vessels, presumably from ischemia with hemorrhage prior to complete occlusion
- Leads to Stellate scars (central area of necrosis with radiating star-like pattern composed of straight line)
- Acentuação purpúrica do padrão de livedo reticularis
- Non-inflammatory (ischemic vasculopathy)
- Inflammatory (medium vessel vasculitis)
DDx pela morfologia
DDx: platelets (thrombocytopenia or abnormal function)
DDx (trauma, défice coagulação)
DDx (leukocytoclastic vasculitis)
DDx
Abordagem/estudo
DDx
- Distribuição
- Generalizada - ITP, TTP, SJS, Coagulação intravascular disseminada, Purpura fulminans
- Predominantly acral
- Involving ears and nose → triggered by cold
- Just hands and feet
- Pauci-random (ANCA vasculitis)
- Multidependent
- Cutaneous small vessel vasculitis
Hemostase
- Primária
- Vasoconstriction (endothelium) → adhesion → degranulation (ADP, TXA2) → aggregation
- Secundária
- Antiagregants
- Aspirin: inhibits cyclooxygenase
- Dipyridamle and pentoxyfylline: increase cAMP
- Clopidogrel: blocks ADP
- Anticoagulants
- Dabigatran: inhibit thrombin
- DOACs: inhibit factor Xa (apiXaban, ravaroXaban)
- Unfractionated heparin: activates antithrombin
- LMWH (enoxaparin), mainly inhibits factor Xa
Score para avaliar o grau de hemorragia para perceber se é uma hemorragia grave ou só uma coisa simples:
Approach to purpuras
Autoimmune | Physical | Hematologic |
Vasculitis | Traumatic Actinic/senile Nutritional Stasis (BPP) Depositional | Platelet dysfunction • Meds • Leukemia • Autoimmune • Infectious • Renal Clotting factors • Nutritional • Meds • Consumptive • Hypercoagulable • Manufacturing or metabolic |
Petechiae | Púrpura | Ecchymoses |
Thrombocytopenia • Accelerated platelet destruction ◦ Immunologic: ITP, SLE, AIDS ◦ Non-immunologic: TTP, DIC • Deficient platelet production: myelogenic Abnormal platelet function • Hereditary platelet defects • Drug-induced • Renal failure, uremia Non-platelet related • Pigmented purpuras • Waldenstrom’s macroglobulinemia • Fixed pressure increases (e.g. sneezing) • Trauma • Vit C deficiency | Palpable purpura • Leukocytoclastic vasculitis • Small and medium vessel vasculitis • Cryoglobulinemia Retiform purpura • Trombóticas: Alterações da coagulação: coagulação intravascular disseminada, TTP/HUS, trombose induzida por fármacos (varfarina ou heparina), hypercoagulable states • Embólicas: êmbolos cardíacos, endocardite bacteriana ou marantica, mixoma auricular, êmbolos de colesterol depois de procedimentos endovasculares (também causam eosinofilia, LRA, AVC, isquémia intestinal, amausosis fugax) • Cryoglobulinemia, cyofibrignemia, cold agglutinins • Calciphylaxis • Medium vessel vasculitis • Cocaine-induced | Anticoagulant use Hepatic (synthetic) insufficiency Vitamin K deficiency DIC Actinic or senile purpure Vitamin C deficiency Systemic amyloidosis |
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