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Purpura is a group of diseases characterized by skin petechiae and may be associated with other local or systemic manifestations.

Petechiae are small, purpuric lesions up to 2 mm across while ecchymoses or bruises are larger extravasations of blood.

Purpura is normally distinguished from erythema when pressure is applied by finger or by pressure of a slide on the erythematous patch (diascopy )fails to blanch the lesion.

The characteristic color changes in purpuric lesions vary from purple, orange, brown and even blue and green. Discoloration of the skin or mucous membrane is due to extravasations of blood.

Types of Purpura

Classification of purpura is usually unsatisfactory. There are different classifications in the different textbooks depending either on the morphological or etiological characters of these diseases.

  1. Thrombocytopenic purpura

    This type of purpura is related to platelet abnormality either due to reduced formation or their destruction by different factors . Purpura due to platelet deficiency usually occurs with a platelet count below 10000 /mm3 and is seldom observed with a count abov50000/mm3.

    Platelet plug is formed as a result of injury or disease of the vascular wall releasing serotenin and thromboxane A2 causing vasoconstriction and increase adhesion and aggregation of the platelets forming a platelet plug.

    Developing platelet plugs are reinforced by fibrin strands formed as a result of activation of the plasma clotting system by platelet factor3 when this is exposed by alterations in the surface characteristics of the aggregated platelets.


Thrombocytopenia purpura may be primary (idiopathic ) due to unknown causative factors or secondary to different agents.

  1. Idiopathic thrombocytopenia purpura.

    This disorder results from immune destruction of platelets. Viral antigen-antibody reactions may be demonstrated in acute forms of the disease, whilst most chronic cases are associated with antiplatelet autoantibodies. The platelets fall below 50 000/mm3 and may even be absent.

  2. Secondary thrombocytopenia purpura.

    Different external and internal factors may cause thrombocytopenia purpura

  1. Drugs:

    The most common drugs that can cause purpura are:

    Antibiotics: different antibiotics may cause purpura such as: Ampicillin,penicillin,Chloramphenicol, Rifampicines, Sulfonamides and Trimethoprine.

    Analgesics: acetylsalicylic acid , phenylbutazone .

    Other drugs: quinine , quinidine , sedormid and thiazides .

  1. Chemicals: benzol, and snake venom.

  2. Infections: septicemia, typhoid, typhus, smallpox, chickenpox, vaccinia, scarlet fever, influenza, and subacute bacterial endocarditis.

  3. Bone marrow diseases: leukemia, aplastic anemia and pernicious anemia are the commonest causes of thrombocytopenia.

  4. Splenomegaly: may be associated with purpura .

  5. Haemangioma:thrombocytopenia may be associated with haemangiomas.

  6. Wiskott-Aldrich syndrome: (thrombocytopenia, eczema and infections).

  7. Uraemia: that is rare in children in whom thrombocytopenic purpura and bleeding are associated with fever, hemolytic anemia , renal and neurological symptoms.

  8. Physical factors: such as sun stoke .

Clinical Manifestations

Thrombocytopenic purpura may occur at any age, but in two-thirds of cases it occurs in young age . Females are more commonly affected than males.

The onset may be gradual or, acute especially in children. There is an appreciable mortality, especially in the acute form, mainly from cerebrovascular accidents.

Bleeding occurs into the skin with areas of petechiae or larger hemorrhages and may occur in internal organs.

Joint involvement is unusual.

The spleen may be slightly enlarged .

Spontaneous remission occurs in a proportion of acute cases, but is rare in chronic cases of more than 3 months‘ duration in which a continuous or fluctuating course may occur. 


Clinical picture.

Blood picture: low platelet count , Megakaryocytes are present in normal or increased numbers in the bone marrow.

Negative bone-marrow findings.

Differential Diagnosis

Systemic lupus

Drug-induced purpura

Disseminated intravascular coagulation

Renal failure.


  1. Treatment of the cause.

  2. Corticosteroids .

  3. Immunoglobulins .

  4. Splenectomy is of real help in most chronic cases and in acute cases not responding to corticosteroids . After Splenectomy the platelet count tends to remain low but the purpura tends to improve.

  5. Immunosuppressive therapy: is indicated in cases, which fail to respond to splenectomy and steroids or where splenectomy is contra-indicated .

  6. Danazol may be of help in some cases.

Fig. 345. Purpura

Fig.346 Purpura (Vasculitis)

Fig.347.  Vasculitis

Fig. 348. Purpura

Fig. 349. Purpura

  1. Non Thrombocytopenic Purpura

Vascular purpura

Non-thrombocytopenic purpura comprises the vast majority of cases of purpura.

Blood may leak as a result of:

Damage to small blood vessels.

Increase in the intraluminar pressure.

Deficient vascular support.

Bleeding may arise from a disturbance of one or more of the following mechanisms:

  1.  Contraction of the vessel wall.

  2.  Plugging of small vessels by platelets.

  3.  Coagulation of blood.

    Often all these factors operate together and the exact role and importance of each in the pathogenesis of the purpuric reaction varies.

    Other factors leading to these disturbances are multiple and obscure.

Etiology of Vascular Purpura.

  1. Damage to the blood vessels.

    Capillary fragility depends upon numerous factors, including the integrity of the capillary endothelium itself and also the ability of platelets to fill any gaps, which may arise in it .

    The capillary resistance can be determined by a simple test called Hess test. This can be achieved by inflating a sphygmomanometer cuff around the upper arm to a constant pressure of 80 mm of mercury (or less if this approaches the systolic blood pressure) for 5 min.

    Petechiae may develop in the presence of abnormalities of the vascular wall, thrombocytopenia or platelet dysfunction, and can be counted after releasing the pressure. Up to five in a measured area 5 cm across just below the ante cubital fossa may be considered normal. Raised intravascular pressure may cause purpura in the absence of any other disease.

    Simple petechial lesions may develop after prolonged coughing, vomiting or by pressure on localized area of the skin .

    Direct damage due to a trauma or secondary to different factors as immunological factors in Schwartzmann phenomenon that is due to antigen-antibody reaction causing hemorrhagic necrosis of arterioles and venules.

  2. Raised intravascular pressure.


    • Hypertension.

    • Gravity and venous stasis are most important causes of purpura.

    • Suction of a certain part of the skin may cause localized purpura such as in self-inflicted lesion , in dermatitis artefacta.

    • Different physical factors as cold , pressure , trauma or change in gravity.

    • Infections.

    • Additives to food and beverages due to tartrazine and other food additives.

  3. Drugs

    Different drugs and toxins may cause purpura which are mainly the following:

    Arsenic, atropine, bismuth, barbiturates, carbromal, chloramphenicol, chlorothiazide, chlorpromazine, di-ethyl stilboestrol, gold, hair dye, isoniazid, iodides, menthol, meprobamate, paraaminosalicylic acid, piperazine, quinidine, quinine, reserpine, snake venoms, sodium salicylate, sulphonamides, , thiouracil, tolbutamide and glyceryl trinitrate.

    Corticosteroids Purpura

    This type of purpura is due to lack of support of the blood vessels. Strong potent topical steroids as Colbetasol used for a long time can cause local dermal collagen atrophy, telengectasia where the blood vessels looses their support, become fragile and rupture causing local purpuric rash.

  4. Solar Radiation

    Prolonged exposure to sun will also lead to collagen atrophy leading to loss of support to the dermal arterioles and venules.

    This type of purpura occurs mainly on sun-exposed parts of the hands and forearms or on the legs. Lesions appear after minor trauma or apparently spontaneously.

  5. Scurvy purpura

    The support for the blood vessels is abnormal in scurvy. Either small or large bruises may appear on the limbs with mild trauma. Petechial hemorrhages may also occur, especially on the legs and from the gums.

  6. Toxic purpura

    Capillary damage may be direct due to certain toxins that cause toxic effect to the vascular wall or due to an allergic reaction without any change in the platelet count or morphology .

    Drugs such as certain antibiotics (chloramphenicol, sulphonamides) quinine, carbromal and barbiturate may cause capillary damage.

  7. Contact purpura

    Certain substances may cause contact purpura such as azodyes, rubber additives, certain clothing (khaki cloth) used by the army.

  8. Purpura associated with infections

    Purpura may be associated with infection such as septicemia, meningococcal, rickettesial, viral infections and subacute bacterial endocarditis. The purpura may also appear in the prodromal period of many infections such as measles, where this is often a sign of a severe infection.

    Purpuric eruptions may also be found in the course of candidal infections.

  9. Purpura associated with systemic diseases

    Non-thrombocytopenic purpura may be caused by a variety of systemic diseases. The mechanism of capillary damage is unknown.

    The common systemic diseases associated with purpura are:


    Liver diseases


    Hemochromatosis and carcinomas.

    Amyloidosis due to infiltration of the capillaries with amyloid.

    Malnutrition: It seems probable that changes in coagulation, platelets and capillaries all play their part.

    Fat embolism:Petechiae, which may be few or very numerous, are an important sign . They occur particularly on the upper part of the body 2-3 days after a major injury. Minute fat emboli have been found within the vessels at the sites of the petechiae.

    Endocrine abnormalities: such as in Cushing‘s disease. 



Purpura may be the presenting and sometimes the only symptom of disturbances in plasma proteins.

It may occur with cryoproteinaemia. This type appears most commonly on the unprotected parts after exposure to cold.

Hyper globulinaemia due to different causes such as idiopathic (Waldenstrom‘s) sarcoid, lupus erythematosus, Sjogren‘s syndrome, myeloma, may give rise to purpura. The clinical features of dysproteinaemic purpura are erythematous papules that occur mainly on the legs and rapidly progress to form punctate purpuric lesions

In mild cases the eruption disappears within few days, but in more severe cases the purpura becomes confluent and permanent.

A similar pattern has been reported in association with cystic fibrosis, whether or not associated with cryoglobulinaemia. 


(Anaphlactoid purpura)

This type affects children and young adults . Urticaria and purpura with multisystmes involvement of kidneys, bowel and joints characterize this type of purpura.


Damage to the walls of small blood vessels due to deposition of immune-complex substances.

Cryoglobulins have been found rather than the immune complexes.

An antigen associated with upper respiratory tract infection is suspected to be part of the usual cause of the immune response.

Clinical Manifestations

General manifestations:

The manifestations usually begin with mild fever, sore throat, and upper respiratory tract infections which may precede the skin rash.

Skin manifestations:

Macular rash appears first on the extensor surfaces of the limbs and buttocks, which becomes rapidly, urticarial and purpuric with central necrosis of the lesions.

Systemic manifestations

Renal involvement, which is focal nephritis. This is a serious manifestation of the disease.

Bowel involvement leads to abdominal colic and hemorrhage.

Polyarthritis and pain in the joints are another manifestation.

The course of the disease is chronic . It may take weeks for regression of the skin lesions, but usually there is recurrence.

Renal and bowel manifestations may improve or may cause serious complications.



These are vascular diseases of undetermined cause with different manifestations and share the same histopathological features.

These include different diseases mainly:

Schamberger‘s Disease

This is a progressive pigmented purpuric dermatosis of unknown etiology, affecting male children and other age groups that may show familial incidence.

Clinical Manifestations

The skin lesion is irregular brown plaques that may present with different pigmentations due to hemosidrin deposits. ‘Cayenne pepper‘ spots characterize the lesions.

The condition is usually asymptomatic , although there may be some slight itching. The eruption is characteristically very chronic and may persist for many years. The pattern of the eruption changes where these may show slow extension with some clearing of the original lesions. Spontaneous cure may occur eventually.

Differential Diagnosis

Drug eruption: different types of drugs particularly carbromal and other drugs may cause similar types of purpuric skin lesions.

Food allergy and food additives.

Clothing dermatitis.

Hyperglobulinaemic purpura.

Early mycosis fungoides .


(Eczematide-like purpura )

Itching purpura is an eczema like purpura, which begins usually as an eczematous purpuric reaction around the ankles and spreads peripherally.

The eruption often has a rather characteristic orange color.

Eczematous skin lesions presenting as erythematous purpuric macules that may simulate shoe dermatitis or drug reaction. The condition rarely becomes generalized, affecting mainly exposed areas due to chaffing or friction.

Spontaneous improvement is usual, but recurrences may occur.

Differential Diagnosis

Drug reactions:Carbromal sensitivity, Meprobamate and Carbamazepine.

Food allergy .

Clothing or rubber contact dermatitis.

Schamberg‘s disease is distinguished by its more persistent course and by the usual lack of itching.


( Lichen purpuricus)

This is a more localized, more intensely purpuric eruption.

Clinical Manifestations

Skin lesions begin as rust-colored to purple non-itchy solitary macules, seldom truly golden, which may resemble a bruise. Small vesicles may be seen in its course of the disease, that may persist for few years.

Histopathological changes are in the form of capillaritis, infiltration with lymphocytes and histocytes.


Topical steroids may be helpful.


( Majocchi's disease )

This type of capilliritis may show familial tendency that affects mainly young adults of both sexes, where any age is not immune.

Clinical Manifestations

Lesions occur at any site, often in the absence of venous stasis and may be few in number or very numerous. Skin eruption presents with small annular plaques, telangiectasia and haemosidrin deposits causing purple, yellow or brown patches that may contain ‘cayenne pepper‘ spots.

Individual lesions persist unchanged for many months or years, or there may be slow centrifugal extension. Sometimes the lesions disappear and may recur with the same eruption.


The lesions are asymptomatic and rarely treatment is needed .



These diseases are due to defects in one or more of the numerous factors related to clotting with abnormalities of the platelet functions .



Vascular purpura is uncommon in the neonatal period but may occur.

Hemorrhagic disease of the newborn is due to an accentuation of the normal fall of prothrombin within the first week of life.

Differential Diagnosis

Purpura or bleeding within the first month of life should be differentiated from different types of purpuric skin diseases:

Deficiency of the clotting factors .

Deficiency of the protein S or protein C.

Hemophilia and other bleeding diseases, which rarely cause bleeding at this age.

Thrombocytopenia may be due to congenital failure of megakaryocytes.

Immunological mechanism in a child whose mother has idiopathic thrombocytopenic purpura or systemic lupus erythomatosus.

Neonatal rubella and Wiskott-Aldrich syndrome.




Cutaneous systemic angitis is a complex and widespread necrosis of the small blood vessels.


Different factors are blamed to be the cause of systemic angitis.

These include:

Drugs: the most common drugs which can cause systemic angitis are :sulfonamides, acetylsalicylic acid (Aspirin), phenothiazines, barbiturates.

Infections: Streptococcal infection , pyodermas , upper respiratory tract infection .

Insecticides and weed killers.

Cutaneous systemic angitis includes different diseases mainly :

  • Allergic vasculitis

  • Hypersensitivity angitis

  • Systemic allergic vasculitis

  • Periarteritis nodosa

  • Allergic angitis

  • Dermatitis nodularis chronica

  • Arteriolitis allergica



Purpura fulminans is a serious disorder affects patients of different ages, but most commons in children.

Clinical Features

Lesions are characterized by the development of more or less symmetrical and well-defined “lakes“ of confluent ecchymosis without petechiae mainly on limbs, trunk and face.

The onset is sudden, and the lesions enlarge rapidly, with coalescence and often with the development of hemorrhagic bullae and central necrosis. There is a surrounding erythema and the lesions are tender. The patient is frequently febrile. Vascular thrombosis is a particular feature of this disorder.

There is a substantial danger of internal hemorrhage, shock and death. 


In older children, purpura fulminans may have several causes. It is a highly characteristic feature of meningococcal septicemia and may occur as a sequel to a number of other infections, including common infections such as streptococcal infections, varicella, and measles. In the neonate, however, its occurrence is very suggestive of protein C deficiency .


Treatment comprises rapid transfusion of fresh frozen plasma.



It is a distinctive disorder, comprising a combination of purpura, often in a cockade pattern, and an inflammatory edema of the limbs and face, occurring almost exclusively in children under the age of 2 years, with a tendency to recurrence in the short term and subsequent spontaneous resolution .

The cause of infantile hemorrhagic edema remains unknown, though it may represent an infantile analogue of Henoch-Schonlein purpura.


(Purpura Fulminans)

Disseminated intravascular coagulation may produce a clinical picture varying from a severe and rapidly fatal disorder to a relatively minor disorder.

Predisposing Factors

This is due to congenital or an acquired deficiency of the protein S and protein C components of the anticoagulation system.


The causes of disseminated vascular coagulation are:

Extensive tissue damage .

Severe infections (especially Gram negative septicemia).

Immune reactions.

Malignant disease.

Snake bites.

Giant haemangiomas.

The normal inhibitory mechanisms of clotting are over-coming, so that there is intravenous coagulation, followed by consumption and depletion of platelets and plasma clotting factors.

Clinical Manifestations

The manifestations include bleeding, thrombo-embolism and hemolytic anemia.

The onset may be acute, sub acute or chronic.

Mild cases: show petechiae, purpuric papules, hemorrhagic bullae and acral cyanosis. There is decreased fibrinogen and increased fibrin degradation products. Skin biopsy may be useful in showing intravascular thrombi.

Severe cases: the onset is sudden, with high fever and a very extensive, usually symmetrical, purpuric rash of the extremities.

A fatal outcome may follow within 2 or 3 days.


Treatment of shock and replacement therapy with platelets, fibrinogen, and fresh frozen plasma.

Symptomatic treatment.

Treatment of the cause.

The role of heparin is still somewhat controversial.



Skin manifestations

The lesion usually begins in the lower legs, buttocks , hands and wrists. Mucous membrane lesions are rare. Different skin lesions may appear either purpuric rash, hemorrhagic vesicles and bullae may develop. Finally there are nodules and ulceration, which persist for a long period .Usually one type of these lesions, manifest either purpuic rash alone or vesicular type.

General manifestations

Fever, malaise and myalgia are frequent symptoms .

Burning sensation and pain may be mild or sometimes severe depending on the site and extent of the lesions.

Arthralgia and swollen joints.

Kidney involvement : leads to manifestations of glomerulonephritis.

Gastrointestinal manifestations: haematemesis, melena, peptic ulceration, esophageal ulceration. These usually manifest with nausea , vomiting , diarrhea and anorexia .

Congestive heart failure manifestations.

Lung involvement leads to pneumonitis.

Eye changes: retinal hemorrhage.

Neural manifestations: peripheral neuritis , diplopia , dysphagia and hoarseness of the voice.


Laboratory Tests:

ESR: is usually elevated


IgG globulin and C3 complement appear in the areas of fibrinoid necrosis of the blood vessels .


Treatment of the cause.

Corticosteroids may help some cases.



Cutaneous vasculitis is characterized by purpuric or necrotic urticarial lesions and may be associated with vasculitis of internal organs.

Histopathological changes of cutaneous vasculitis are characteristic.

These include fibrinoid changes in the small dermal blood vessels with polymorphonuclear and ‘nuclear dust infiltrate.

Blood Picture.

The ESR may be normal, but is usually raised. When ESR is much raised in urticarial vasculitis, lupus erythematosus should be excluded.

Neutrophilia or eosinophilia may occur.

Hypocomplementaemia is usual.

Circulating immune complexes are often demonstrated .

Differential Diagnosis

Infection, drug intake, internal neoplasia or collagen disease, where these may show cutaneous vasculitis and should be excluded .



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