Purpuric Rash - Types, Causes, and Management

Introduction:

Purpura is a type of rash that occurs due to bleeding in the skin. When these rashes are less than one centimeter in diameter, they are called petechiae. When these purpura are large and intense, they are called ecchymoses. Purpuric rashes can range from four to 10 centimeters in diameter. Platelets play an important role in clotting as well as adhesion of capillary lining. Therefore, in some cases, deficiency in the platelet system can cause purpura. Therefore, purpura can occur due to normal platelet counts called non-thrombocytopenic purpuras or due to low levels of platelets called thrombocytopenia purpura. Purpuric lesions can occur without any underlying disorder and are mostly affected by women.

What Is a Purpuric Rash?

A purpuric rash is a type of condition of the skin which causes purplish discoloration, and there is the presence of blood vessels near it. Purpuric rashes can also occur in the internal organs, mucous membranes, or mouth. Purpuric rash is not a disorder; instead a symptom of the bleeding that occurs in the mucosa or the skin.

What Is the Appearance of Purpuric Rash?

The purpuric rashes appear as purplish red to brownish black. They are flat and can appear as large spots or many small dots. The characteristic feature of purpuric rash is that it does not blanch (become pale) when pressure is applied to it. Purpuric rashes can develop anywhere on the skin of the leg, trunk, or hand.

What Are the Types of Purpuric Rash?

The types of purpuric rash based on platelet count are:

• Non-Thrombocytopenic Purpura: This occurs when the platelet counts are at normal levels. It can be due to congenital causes, infections such as meningococcal infections, allergic reactions, or drug-induced.

• Thrombocytopenia Purpura: This occurs when the platelet counts are low. It can be due to impaired production of platelets or excess tear-down of platelets.

• Purpura Due to Coagulation Disorder: This includes heparin-induced thrombocytopenic purpura, which occurs due to a block in blood vessels due to anti-platelet antibodies, Warfarin-induced necrosis, and disseminated intravascular coagulation (DIC) occurs due to abnormal blood clot.

What Are the Causes of Purpuric Rash?

The causes of non-thrombocytopenic purpura are:

a. Congenital causes (present by birth) -

Connective tissue disorders such as -

• Pseudoxanthoma Elasticum: A type of disorder that occurs due to increased amounts of calcium in the elastic fibers which are a type of connective tissue.

• Ehlers-Danlos Syndrome: A type of disorder characterized by hyperelasticity of skin along with fragile blood vessels.

• Hereditary Hemorrhagic Telangiectasia: A genetic disorder that causes arteriovenous malformations.

• Congenital Cytomegalovirus (CMV): A type of intrauterine infection that causes hearing loss.

• Congenital Rubella: A type of intrauterine infection that occurs due to the rubella virus.

b. Acquired causes -

• Meningococcal Infections: A bacterial infection caused by Neisseria meningitidis.

• Measles: A type of viral infection.

• Streptococcal Septicemia: Infection in the blood due to a bacteria called Streptococcus agalactia.

• Diphtheria: Caused by Corynebacterium diphtheriae bacteria.

• Acute viral infections such as chicken pox, measles, smallpox, and parvovirus B19 can also cause purpuric rashes.

c. Allergic causes -

• Henoch-Schonlein Purpura: A type of blood vessel inflammation that occurs bleeding in the skin, kidneys, intestines, and joints.

• Systemic Lupus Erythematosus (SLE): A type of autoimmune disorder that affects the organs such as blood vessels, joints, lungs, kidneys, and brain.

• Rheumatoid Arthritis: An autoimmune disorder that affects the joints.

d. Drug-induced causes -

• Sulfonamides.

• Steroids.

e. Other causes -

• Senile Purpura: It occurs due to long exposure to the sun.

• Scurvy: A disorder that occurs due to a lack of vitamin C.

• Factitious Purpura: A type of purpura that is inflicted by the patient itself.

• Trauma.

The causes of thrombocytopenic purpura are:

a. Due to impaired production of platelets include -

• Generalized bone marrow failure such as:

1. Leukaemia: A blood cancer.

2. Myeloma: A plasma cell (white blood cells) cancer.

3. Aplastic Anemia: A condition in which blood cells are not produced enough by the bone marrow.

4. Marrow infiltration by solid tumors.

b. Due to reduction in megakaryocytes include:

• Viral infections.

• Drugs such as Co-Trimoxazole.

c. Due to excessive destruction of platelets include -

• Immune problems such as:

1. Immune Thrombocytopenia: A type of blood disorder in which platelet counts are low. Immune thrombocytopenic purpura occurs due to cytotoxic T cells.

2. Secondary Immune Thrombocytopenia: It occurs due to exposure to drugs or viral infection.

• Coagulation problems such as:

1. Disseminated Intravascular Coagulation (DIC): A life-threatening disorder that causes clotting in the body.

2. Hemolytic Uraemic Syndrome: A type of disorder that occurs due to a block in the urinary system by the red blood cells.

3. Splenomegaly: Enlarged spleen.

4. Dilutional Loss: Occurs due to massive transfusion of blood.

What Is the Management of Purpuric Rashes?

While examining purpuric rash, the nature of the rash, such as size and associated blisters, should be noted. The location of the rash should also be noted; if confined to one place, it can be due to trauma, and if seen in the lower legs, it can be due to venous hypertension. Lesions should be examined in the mucous membrane also; if associated with pain, it suggests inflammation. Apart from these, the age (Henoch-Schonlein purpura occurs in kids, and senile purpura occurs in aged persons), duration (in the case of meningococcal septicemia, the rash appears spontaneously), and travel history should be noted. Investigations should be done such as:

• A diascopy test with the help of a glass slide is performed, which shows the blanching of the rash when pressure is applied.

• Full blood count (FBC), erythrocyte sedimentation rate (ESR), and platelet counts should be diagnosed. An increased ESR rate indicates inflammation. An increased platelet count can be due to leukemia or anemia.

• Liver function tests (LFT) are done in case of liver disorder.

• A coagulation test in case of clotting factor deficiencies.

• INR (international normalized ratio) blood test, a type of blood clotting test, should be checked in the case of patients on warfarin.

• A plasma electrophoresis test should be done in case of hypergammaglobulinemia (increased levels of immunoglobulins) or cryoglobulinemia (abnormal proteins in the blood).

• Autoantibody testing should be done in case of connective tissue disorders such as pseudoxanthoma elasticum.

The management of purpuric rashes includes:

• Before treatment, the underlying cause should be identified and treated.

• If the purpuric rash is because of a low platelet count (below 30 x 109 per liter) an emergency treatment should be provided.

• In case of the underlying cause of splenomegaly (enlargement of the spleen), splenectomy (a surgical procedure in which the spleen is partially or completely removed) should be performed.

• If the person is taking Ibuprofen, Aspirin, or blood thinners, the medications should be changed.

• Corticosteroids can help in increasing the platelet count by stopping it from getting destroyed.

• Intravenous immunoglobulin (IVIg) can also help in increasing the platelet count, but the effects are of short duration.

• Other medications, such as Romiplostim and Eltrombopag, can be given, which help in increasing the production of platelets in the bone marrow.

• In the case of patients for whom corticosteroids do not work well, Rituximab is given. This is used in cases of severe thrombocytopenic purpura.

Conclusion:

Purpuric rashes are seen in all age groups; adults are more affected by this. In kids, the recovery takes place quickly, whereas, in adults, it can be due to an underlying disorder. Most purpuric rashes fade away on their own, but some may require one to three weeks to fade away; if not, the cause should be treated. The prognosis of the purpuric rash depends on the underlying condition. In the case of bleeding disorders, if the treatment is delayed, it can cause severe fatal bleeding.