History and exam

Key diagnostic factors

common

presence of risk factors

Key risk factors include autoimmune disorders, lymphoproliferative disorders, mechanical prosthetic heart valves, family origin in Mediterranean, Middle East, sub-Saharan Africa, or Southeast Asia, family history of haemoglobinopathy or red blood cell membrane defects, paroxysmal nocturnal haemoglobinuria, thermal injury, or recent exposure to cephalosporins, penicillins, quinine derivatives, non-steroidal anti-inflammatory drugs, naphthalene, or fava beans.

pallor

Non-specific sign of anaemia.

jaundice

Due to increased bilirubin from red blood cell destruction.

Other diagnostic factors

common

fatigue

Non-specific sign of anaemia.

shortness of breath

Non-specific sign of anaemia.

dizziness

Non-specific sign of anaemia.

splenomegaly

Non-specific sign. May be present in hereditary spherocytosis, non-Hodgkin's lymphoma, or portal hypertension due to cirrhosis.[38]

uncommon

active infections

Direct parasitic destruction of the red blood cell (RBC) caused by agents such as malaria, Babesia, or Bartonella.[32][33]

Infection-related toxins can produce direct lysis of RBC, as in clostridial sepsis.

Also associations with pneumococci, Escherichia coli, and staphylococci.

May be present in mild or localised infection as well as in systemic, severe infection.

episodic dark urine (haemoglobinuria)

Suggestive of paroxysmal nocturnal haemoglobinuria.

triggered by exposure to cold

Donath-Landsteiner antibody (cold agglutinins) may be present.

Risk factors

strong

autoimmune disorders

Systemic lupus erythematosus (SLE), rheumatoid arthritis, and scleroderma are associated with an increased incidence of warm autoimmune haemolytic anaemia due to autoantibody production.[10][11] The incidence of clinically significant haemolytic anaemia has been described in up to 10% of patients with SLE.[13] On a lesser scale, other entities such as rheumatoid arthritis, scleroderma, dermatomyositis, and inflammatory bowel disease have an increased incidence of autoantibody formation.[14]

lymphoproliferative disorders

Oncology patients, specifically patients with chronic lymphocytic leukaemia (CLL), non-Hodgkin's lymphoma (NHL), and plasma cell disorders, often develop warm autoimmune haemolytic anaemia (AIHA).[15][16][17][18][19]

Estimates of the incidence of AIHA are 7% to 10% in patients with CLL and 3% in patients with NHL.[15][16]

prosthetic heart valve

Haemolysis is a well-described entity in patients with mechanical prosthetic heart valves, but incidence has declined due to improved surgical technique and valve design.[20][21]

Subclinical haemolysis is not uncommon, even with more contemporary prostheses (≥5% in some studies).[22]

family origin in Mediterranean, Middle East, Africa, or Southeast Asia

Haemoglobinopathies (thalassaemia, sickle cell anaemia) are more common in groups originating in these areas.[23][24]

Africa is the World Health Organization region with the highest incidence of glucose-6-phosphate dehydrogenase deficiency; it is very common in the sub-Saharan region.[3][4][Figure caption and citation for the preceding image starts]: Digitally-colourised scanning electron micrograph showing normal red blood cell (RBCs) and a sickle cell RBC (left) in a blood specimen of patient with sickle cell anaemiaCDC/ Sickle Cell Foundation of Georgia: Jackie George, Beverly Sinclair [Citation ends].com.bmj.content.model.Caption@5e4ecaed

family history of haemoglobinopathy or red blood cell membrane defects

Suggests heritable causes of haemolysis, such as glucose-6-phosphate dehydrogenase deficiency, thalassaemia, or sickle cell anaemia.[1]

paroxysmal nocturnal haemoglobinuria

A rare disorder resulting in an acquired red blood cell membrane defect and subsequent haemolysis. Characterised by haemolysis, increased risk of thrombosis, and bone marrow failure.[25]

recent exposure to cephalosporins, penicillins, quinine derivatives, or non-steroidal anti-inflammatory drugs

Many drugs have been implicated in immune responses resulting in haemolysis.[12][26] Cephalosporins in particular have been associated with significant haemolysis, including fatal cases.[27] If haemolytic anaemia is diagnosed and drugs are suspected as the inciting event, a comprehensive search of the patient's medications should be conducted.

recent exposure to naphthalene or fava beans

May trigger haemolysis in glucose-6-phosphate dehydrogenase (G6PD) deficiency.[28] Naphthalene is found in moth balls.

G6PD deficiency is the most common deficiency of erythrocyte enzymes that results in a shortening of the erythrocyte lifespan.

thermal injury

Can cause haemolysis by disruption of red cells by microangiopathic processes.

weak

exceptional exertion

Circulatory trauma may lead to footstrike (march) haemolysis.[29]

recent exposure to nitrites, dapsone, ribavirin, or phenazopyridine

Medications can induce non-immune destruction of red blood cells, usually by oxidative stress.[30]

recent paraquat ingestion

Herbicides can induce non-immune destruction of red blood cells, usually by oxidative stress.[31]

malaria

Direct interaction between the infective organism and the red blood cell is responsible for haemolysis.[32][Figure caption and citation for the preceding image starts]: A photomicrograph of a blood smear showing erythrocytes containing developing Plasmodium vivax parasitesCDC/ Dr Mae Melvin [Citation ends].com.bmj.content.model.Caption@2ecae3f8

babesiosis

Direct interaction between the infective organism and the red blood cell is responsible for haemolysis.[33][Figure caption and citation for the preceding image starts]: Photomicrograph revealing the presence of what were determined to be numbers of intraerythrocytic Babesia sp. ring-form parasitesCDC/ Dr Mae Melvin [Citation ends].com.bmj.content.model.Caption@22b9384f

bartonellosis

Direct interaction between the infective organism and the red blood cell is responsible for haemolysis.

leishmaniasis

Direct interaction between the infective organism and the red blood cell is responsible for haemolysis.

Clostridium perfringens infection

Toxin production due to phospholipase C (alphatoxin) can cause massive haemolysis in rare instances.[34][35]

Haemophilus influenzae type B infection

Capsular polysaccharide binds with the red blood cell membrane, and infected patients form antibodies to this complex.[36]

liver disease

May be associated with splenomegaly and haemolysis. Alcoholic cirrhosis in particular results in structural changes to the red blood cell membrane and subsequent haemolysis.

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