SCD & Thalassemia Flashcards
SCD and thalassaemia are both types of what?
Congenital anaemia
What is the mode of inheritance of both SCD and thalassaemia?
Autosomal recessive
Where does the mutation occur in SCD, and what does it result in?
Mutation occurs on HB’s beta chain
Results in RBCs being of a sickle shape
What Hb chain does SCD mutate?
Beta chain
What are the 2 main features of SCD?
Haemolysis
Vado-occlusions
I’m young patients with SCD, what can occur which is a clinical emergency?
Splenic infarction
If osteomyelitis was to occur in patients with SCD, what is the likely cause?
Salmonella
What are the clinical features of SCD?
Bone pain
Leg ulceration
Hyposplenism
Pigmented gallstones
Chest crisis can occur in SCD. What are the triad of symptoms?
Worsening hypoxia
Chest pain
Fever
If an SCD patient presents with chest pain, worsening hypoxia and fever, what is this presentation called?
Chest crisis
What are the risk factors of SCD in terms of:
A. Ethnicity
B. Geography/climate
A. Afro-Caribbean
B. Areas where malaria is common
What ethnicity is most at risk of SCD?
Afro-Caribbean
What parasitic infection are sufferers of SCD protected from?
(Same as in G6PD deficiency)
Malaria
What is the common cause of the severe bone pain in SCD?
Femoral head necrosis
If an SCD patient presents with chest crisis or just severe pain, what would you give them?
Analgesia (within 30mins)
Oxygen & rehydration
Antibiotics (consider)
How is severe SCD treated?
Blood transfusions
Splenectomy
What is given for the long term prophylaxis of SCD?
Folic avid
Penicillin
Hydroxycarbamide
Vaccinations
What are some complications that can occur in SCD?
ATE or VTE (due to vasoccluions)
Chest crisis
Splenic infarction
Why may a splenectomy be done prophylacticaly for SCD sufferers?
To prevent splenic infarction occurring
How does thalassaemia affect the HB chains?
They are reduced or absent
What Hb chains does thalassaemia affect?
Both alpha and beta chains
If alpha chain -> alpha thalassaemia
If beta chain -> beta thalassaemia
What are the 2 types of thalassemia?
Alpha and beta
What does thalassemia look like on a blood film?
Microcytic
Hypochromic
In severe thalassaemia, severe clinical features can occur, what are they?
Bone deformities
Growth retardation
Splenomegaly
In severe thalassemia, what sorta appearance occurs on bone marrow?
‘Hair on end’
What can occur in children as young as 10 with thalassaemia if it is not treated?
Death
How is thalassaemia treated?
Regular blood transfusions
How often should blood transfusions occur in thalassaemia sufferers?
4-6 per week
What must thalassaemia patients get before getting a blood transfusion and why?
Iron chelation therapy
As this therapy increases the excretion of Fe, otherwise the transfusion will cause an De overload
What is the main cause of sickle cell crisis?
Splenic infarction
What is the collective term for haemophilia and thalassemia?
Haemoglobinopathies
How is sickle crisis treated?
IV fluids Oxygen Hydration Analgesia Blood transfusion
What are signs of SCD on the... A. Skin B. Kidney C. Biliary tree D. Bone
A. Chronic leg ulcer
B. Papillary necrosis
C. Pigmented gallstones
D. AVN of femoral head
How does SCD usually present as?
Worsening pain that doesn’t respond to analgesia
What are the main 2 triggers for an SCD crisis?
Hypoxia
Dehydration
Why should you always check SCD patient’s vision?
Retinopathy can occur
Why should you always check SCD patient’s LFTs?
Liver failure can occur
Why should you always check SCD patient’s X-rays?
AVN of femoral head can occur
Why should you always check SCD patient’s RFTs?
Papillary necrosis can occur
Why should you always check SCD patient’s Well’s score, D-dimer and V/Q scan?
PE can occur
Why should you always check SCD patient’s cerebral doppler USS?
Stroke can occur
What is it called when a lot of sickle cells clump together?
Sickling
Why should you always check SCD patient’s blood results?
Hyposplenism occurs
Why do SCD patient’s need lifelong antibiotics (penicillin)?
As hyposplenism occurs, so they need protection from infection ehhh
What vaccinations are SCD patients given?
Pneumococcal
Haemophilis inlfuenzae
Meningiococcal
What are the long-term treatments for SCD?
Penicillin
Folic acid supplements
Vaccinations
Hydroxycarbamide
Why must SCD sufferers get genetic counselling if they wanna have a baby?
As SCD can merit a TOP (termination of preggers)
What is the likely cause of leg pain in SCD?
Femoral head AVN
Africans are obvs most commonly affected by SCD (same as thalassemia), but why might they not want to get tested or say they have it?
As there’s a stigma attached
If an adult presents with microcytic and hypochromic anaemia, but is not Fe deificent or is in anyway symptomatic and has never had any childhood issues, what is the likley diagnosis?
Thalassemia Trait
carrier of the gene but asymptomatic
Where in the world is thalassemia most common?
these are the areas that you must be extra vigiliant about
West Africa
SE Asia
The Med (Greece)
What does thalassmeia mean in latin or greek?
Sea blood
arrrrrrr me harty
What do you look out for in SCD on a blood film?
Howel-Jowell bodies
If Howel-Jowell bodies occur on a blood film, what is it a sign of?
Hyposplenism
Hyposplenism can result in Howell-Jowel bodies on a blood film, what condition cause it?
SCD
Splenectomy
Coeliacs
Amyloidosis
