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Purpura

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From Wikipedia, the free encyclopedia

(Redirected fromPurpura of the nail bed)

Skin discoloration due to underlying bleeding

For other uses, seePurpura (disambiguation).

Medical condition

Purpura

Petechiae and purpura on the lower limb due to infection-associatedvasculitis
Specialty	Dermatology,hematology

Purpura (/ˈpɜːrpjʊərə/^[1]) is a condition of red or purple discolored spots on theskin that do notblanch on applying pressure. The spots are caused bybleeding underneath the skin secondary to platelet disorders, vascular disorders, coagulation disorders, or other causes.^[2] They measure 3–10 mm,^[3] whereaspetechiae measure less than 3 mm, andecchymoses greater than 1 cm.^[4]

Purpura is common withtyphus and can be present withmeningitis caused by meningococci orsepticaemia. In particular, meningococcus (Neisseria meningitidis), aGram-negative diplococcus organism, releases endotoxin when itlyses. Endotoxin activates the Hageman factor (clotting factor XII), which causesdisseminated intravascular coagulation (DIC). The DIC is what appears as a rash on the affected individual.

Classification

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Purpura are a common and nonspecific medical sign; however, the underlying mechanism commonly involves one of:

Platelet disorders (thrombocytopenic purpura)
- Primary thrombocytopenic purpura
- Secondary thrombocytopenic purpura
- Post-transfusion purpura
Vascular disorders (nonthrombocytopenic purpura)
- Microvascular injury, as seen in senile (old age) purpura, when blood vessels are more easily damaged
- Hypertensive states
- Deficient vascular support
- Vasculitis, as in the case ofHenoch–Schönlein purpura
Coagulation disorders
- Disseminated intravascular coagulation (DIC)
- Scurvy (vitamin C deficiency) – defect in collagen synthesis due to lack of hydroxylation of procollagen results in weakened capillary walls and cells
Meningococcemia
Clumpingfibrillary protein deposits caused byAmyloidosis
Cocaine use with concomitant use of the one-time chemotherapy drug and now veterinary deworming agentlevamisole can cause purpura of the ears, face, trunk, or extremities, sometimes needingreconstructive surgery.^[5] Levamisole is purportedly a common cutting agent.
Decomposition of blood vessels including purpura is a symptom of acuteradiation poisoning in excess of 2Grays of radiation exposure. This is an uncommon cause in general, but is commonly seen in victims of nuclear disaster.

Cases ofpsychogenic purpura are also described in the medical literature,^[6] some claimed to be due to "autoerythrocyte sensitization". Other studies^[7] suggest the local (cutaneous) activity oftissue plasminogen activator can be increased in psychogenic purpura, leading to substantial amounts of localized plasmin activity, rapid degradation of fibrin clots, and resultant bleeding. Petechial rash is also characteristic of arickettsial infection.

Etymology and pronunciation

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The wordpurpura (/ˈpɜːrpɜːrə/) comes from Latinpurpura, "purple", which came from ancient Greek πορφύρα.Purpura is amass noun naming the condition or state, not the name of an individual spot (thus there is no *purpurum, *purpura or *purpura, *purpurae count declension).

References

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^"PURPURA English Definition and Meaning | Lexico.com". Archived fromthe original on October 17, 2019.
^"UCSF Purpura Module"(PDF). Archived fromthe original(PDF) on 2013-10-02.
^McKenzie, Shirlyn B. (2014).Clinical Laboratory Hematology. Williams, Joanne Lynne; Landis-Piwowar, Kristin (3rd ed.). Boston. p. 665.ISBN 978-0133076011.OCLC 878098857.{{cite book}}: CS1 maint: location missing publisher (link)
^Robbins basic pathology. Kumar, Vinay; Abbas, Abul K.; Aster, Jon C.; Perkins, James A. (10th ed.). Philadelphia, Pennsylvania. 2017-03-28. p. 101.ISBN 978-0323353175.OCLC 960844656.{{cite book}}: CS1 maint: location missing publisher (link) CS1 maint: others (link)
^Muirhead, Trevor T.; Eide, Melody J. (2011). "Toxic Effects of Levamisole in a Cocaine User".New England Journal of Medicine.364 (24). The New England Journal of Medicine: e52.doi:10.1056/NEJMicm1008722.PMID 21675882.
^Anderson JE, DeGoff W, McNamara M (1999). "Autoerythrocyte sensitization (psychogenic purpura): a case report and review of the literature".Pediatric Emergency Care.15 (1):47–48.doi:10.1097/00006565-199902000-00014.PMID 10069314.
^Lotti T, Benci M, Sarti MG, Teofoli P, Senesi C, Bonan P, et al. (1993). "Psychogenic purpura with abnormally increased tPA dependent cutaneous fibrinolytic activity".International Journal of Dermatology.32 (7):521–23.doi:10.1111/j.1365-4362.1993.tb02840.x.PMID 8340191.S2CID 38433734.

External links

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Classification	D ICD-10:D69 ICD-9-CM:287 MeSH:D011693 DiseasesDB:25619
External resources	MedlinePlus:003232

Evaluating the Child with Purpura Archived 2008-10-16 at theWayback Machine fromAmerican Academy of Family Physicians

Disorders ofbleeding andclotting

Clotting

By cause	Clotting factors Antithrombin III deficiency Protein C deficiency Activated protein C resistance Protein S deficiency Factor V Leiden Prothrombin G20210A Platelets Sticky platelet syndrome Thrombocytosis Essential thrombocythemia DIC Purpura fulminans Antiphospholipid syndrome
Clots	Thrombophilia Thrombus Thrombosis Virchow's triad Trousseau sign of malignancy
By site	Deep vein thrombosis Bancroft's sign Homans sign Lisker's sign Louvel's sign Lowenberg's sign Peabody's sign Pratt's sign Rose's sign Pulmonary embolism Renal vein thrombosis

Bleeding

By cause

Thrombocytopenia	Thrombocytopenic purpura:ITP Evans syndrome TM TTP Upshaw–Schulman syndrome Heparin-induced thrombocytopenia May–Hegglin anomaly
Platelet function	adhesion Bernard–Soulier syndrome aggregation Glanzmann's thrombasthenia platelet storage pool deficiency Hermansky–Pudlak syndrome Gray platelet syndrome
Clotting factor	Hemophilia A/VIII B/IX C/XI von Willebrand disease Hypoprothrombinemia/II Factor VII deficiency Factor X deficiency Factor XII deficiency Factor XIII deficiency Dysfibrinogenemia Congenital afibrinogenemia