Introduction:

• It is red cell extravasation into the mucosa or skin due to defect in vascular integrity. 
• Some of these purpuras are palpable. Causes of palpability include
  • Fibrin deposition
  • Localized edema
  • Significant cellular infiltration
  • Subcutaneous extravasation of RBCs
• Some of these purpuras show signs of inflammation. These signs include
  • Pain
  • Erythema
  • Warmth
  • Localized swelling
• Some of these purpuras are retiform, i.e. show branching pattern. In absence of inflammation, such pattern indicates small vessel occlusion. Retiform pattern with inflammation indicates vasculitis due to immunoglobulin deposition.
• Palpable/ Retiform, non-inflammatory purpuras
  • Dysproteinemia
    • Cryoglobulinemia
    • Waldenstromhyperglobulinemicpurpura
      • Occurs due to polyclonal increase of immunoglobulins
      • Seen in young women
      • Associated with SLE, RA, Sjogren’s syndrome, sarcoidosis and multiple sclerosis
      • Palpable purpura in lower limbs
      • Resolve spontaneously in 7-10 days
    • Light chain vasculopathy
      • Occurs because of precipitation of light chains in skin
      • Non amyloid monoclonal light chain, usually kappa type is involved
      • May develop rapidly progressive renal failure
    • Cryofibrinogenemia
      • Occurs due to abnormal cold precipitable fibrinogen
      • Clinical features include cyanosis, erythema, Raynaud's phenomenon and palpable purpura
      • Seen with collagen vascular disease and malignancies
      • Treated with plasmapheresis, fibrinolytics, stanozolol, immunosuppression
  • Thrombotic
    • Heparin necrosis
      • Present with purpuric plaques which eventually ulcerate
      • Occurs due to delayed hypersensitivity
      • Skin lesions are seen within 1-2 weeks of initiation of therapy
      • May be related to heparin induced thrombocytopenia
    • Coumarin necrosis
      • Lesions initially appear as erythematous plaques/ nodules, which later become hemorrhagic and necrotic.
      • Common in perimenopausal obese women
      • Seen typically 3-10 days after starting anticoagulant treatment
      • Lesions are seen in areas with fat deposition such as breasts, thighs and buttocks.
      • Occur due to rapid decline in levels of protein C and S, which leads to microvascular occlusion.
      • Treatment should include stopping coumarin anticoagulant, surgical debridement and antibiotics to cover methicillin resistant staphylococcus aureus.
    • Protein C and S deficiency
      • Develop warfarin induced skin necrosis and neonatal purpurafulminans
    • Paroxysmal nocturnal hemoglobinuria
    • Antiphospholipid antibody syndrome
    • Livedoidvasculitis
  • Embolic
    • Cholesterol emboli
      • Present with lower extremity pain and lividoreticularis
      • May have gangrene, purpura, ulceration, cyanosis, nodules
      • Treatment with supportive care with proper hydration and dialysis
    • Cutaneouscalciphylaxis
      • Seen in end stage renal disease due to increased PTH.
      • Subcutaneous and vascular calcification leads to thrombo-occlusive disease
    • Emboli from atrialmyxoma
      • Present with palpable purpura, lividoreticularis, macules/ papules, cyanosis, ulcerations
  • Arthropod bites
    • Bed bugs, Cimexlectularis, kissing bug, Reduviidae, spider
• Palpable/ non-palpable inflammatory purpuras
  • Pyoderma gangrenosum
    • Idiopathic disorder
    • Follicular papules and pustules which later ulcerate
    • 50% are associated with ulcerative colitis, arthritis, hematological disorders, and solid tumors
    • Treatment- Wound care, Immunosuppression (Steroids, cyclosporine, dapsone, azathioprine and infliximab)
  • Sweet’s syndrome (Acute febrile neutrophilic dermatosis)
    • Acute onset of painful, erythematous, violaceous papules/nodules/plaques.
    • Associated with fever and neutrophilia.
    • May be associated with autoimmune disorders
    • Treatment- Steroids
    • Other options of treatment include- clofazimine, dapsone, colchicine, indomethacin, cyclosporine
  • Behcet disease
    • Cutaneous lesions- Palpable purpura, infiltrative erythema, papulopustular lesions
    • Typically, also have oral and genital ulcerations
    • Treatment
      • Anti TNF alpha- Infliximab, Etanercept
      • INF alpha
      • Immunomodulators- Thalidomide, IVIg, dapsone
      • Stem cell transplantation
  • Serum sickness
    • Skin lesions include- urticaria, palpable purpura, erythemiamultiforme
  • Henoch- Schönleinpurpura
    • Pediatricvasculitis
    • Presents with acute abdominal pain, purpura in lower limbs and sometimes nephritis/ arthritis
    • Triggers-
      • Viral- HBV, HCV, Parvo, Upper respiratory infection, HIV
      • Bacterial- Streptococcus, Staphylococcus, Salmonella
      • Drugs- NSAIDs, ACE inhibitors, antibiotics
      • Food allergy
      • Vaccinations
      • Insect bites
    • Self limited condition
    • Steroids are given if there is renal involvement
  • Infections (Due to damage to vessels by microbe/ toxins/ immune complex)
    • Bacterial (Purpura fulminans)- Pneumococcus, streptococcus, meningococcus, H. Influenza
    • Viral- Adeno, Entero, Parvo, Measles
    • Fungal- Disseminated candida, aspergillus, histoplasma, fusarium
    • Parasitic- Pneumocystiscarinii, disseminated strongyloidiasis
    • Rickettsial
  • Erythemamultiforme
    • Crops of well demarcated, erythematous target lesions with central clearing
    • Triggers: Infections (HSV), Drugs (Sulphonamides)
    • Severe form is called as Steven Johnson syndrome
    • Treatment- Steroids in severe cases
  • Cutaneouspolyarteritisnodosum
    • Tender erythematous nodules
  • Paraneoplasticvasculitis
    • Seen with paraproteinemia, Ca lung, colon, breast and cervix
  • Drug induced vasculitis
    • Seen with allopurinol, G-CSF, D-Penicillamine, methotrexate, phenytoin, minocycline
  • ANCA associated vasculitis- Wagener's granulomatosis, Churg Strauss, Microscopic angiitis
• Nonpalpable, noninflammatory, round purpuras
  • Increased intramural pressure gradient
    • Purpura occurs because of extravasation of RBCs
    • Examples include- Weight lifting, post emesis facial purpura, prolonged Valsalva, child birth, lower extremity venous incompetence
  • Drug reactions
  • Coagulation disorders
  • Simple easy bruising
    • 1-2 bruises appear spontaneously, which resolve without any specific treatment
  • Decreased vessel integrity without trauma
    • Senile purpura
      • Seen in areas which are exposed to repeated low level trauma (dorsal aspects of hands and forearms)
      • Caused because of atrophy of subcutaneous tissue, which results in inadequate support to subcutaneous blood vessels
    • Excess glucocorticoid
      • Leads to atrophy of collagen fibers
    • Scurvy
      • Decreased collagen which leads to increased blood vessel fragility
    • Systemic amyloidosis
    • Connective tissue diseases- Ehler-Danlos syndrome, pseudoxanthom aelasticum
    • Mitochondrial encephalomyopathy with lactic acidosis and stroke like syndrome (MELAS)
  • Trauma
  • Schamberg disease (Progressive pigmentarydermatosis)
    • “Cayenne pepper” petichae on the background of hyperpigmented brown or orange oval patches
    • Seen in tibial region
• Others:
  • Heredity hemorrhagic telangiectasia(Osler- Rendu – Weber syndrome)
    • Autosomal dominant
    • Mutation in genes endoglin (HHT1) & ALKI (HHT2) which are involved in signaling by TGFβ super family which leads to abnormal blood vessel development
    • Clinical feature
      • Telangiectasia of mucus membrane of nose, mouth, GIT, vagina & skin.
      • They blanch on pressure & bleed easily following minor trauma.
      • Pulmonary & cerebral AV malformation.
    • Treatment
      • Local cautery
      • Oral estrogen –may reduce bleeding

• Giant cavernous hemangioma (Kasabach merit syndrome)
  • Can cause chronic DIC
  • Spontaneous regressive occurs with age
  • Treatment
    • Corticosteroids
    • Antifibrinolytic therapy
    • Cryosurgery/Laser
    • Radiotherapy
  • Psychogenic purpura
    • Self induced/hysterical/religious/autoerythrocyte sensitization