What is Childhood ITP?
by Dr. John Grainger
What is immune thrombocytopenic purpura?
This explains about immune thrombocytopenic purpura (ITP),
which is a blood disorder affecting the platelets. It also explains
what to expect when your child is diagnosed with the condition.
What are platelets?
Platelets are one of the three types of blood cell, along with
red and white blood cells. Platelets are small and sticky and their
job is to prevent bruising and stop bleeding after an injury. Platelets,
like red and white blood cells, are formed in the bone marrow. A
rough idea of how many platelets are circulating in the bloodstream
(platelet count) can be made using a sample of blood. The normal
platelet count is between is 150 to 400 x 109/l. In most
cases of ITP the platelet count is less than 20 x 109/l.
A low platelet count is called ‘thrombocytopenia’.
Immune thrombocytopenic purpura is a medical term for a condition in
which there is bruising (purpura) because there are fewer platelets in the
blood than usual (thrombocytopenic) and is usually caused by something going
wrong with the immune system (the body’s defence against infection) or an
allergic reaction of some kind.
Chronic ITP is the term for ITP that has not gone away on its own after
6 months. Only 1 in 4 children with ITP will develop chronic ITP. The
majority of children with "chronic" ITP will still have some
recovery of the platelet count at a later date and the majority of younger
children will still completely recover after a few years even if the ITP
is still present at 6 months.
How common is ITP and who does it affect?
About four in every 100,000 children develop ITP each year. There
seem to be two groups who develop ITP: young children and young adults.
It is more common in girls than boys.
What are the symptoms of ITP?
Most children with a platelet count of under 20 x 109/l
will have petechiae (pinprick blood spots under the skin) and limited
bruising. Bruising most commonly follows minor knocks ("easy bruising")
but may also occur spontaneously without trauma. Apart from the bruising/
bleeding the children are otherwise well. Common sites of spontaneous
bleeding are the gums and nose. Girls may be troubled with heavy periods.
Less common and potentially serious are spontaneous bleeds occurring
from the gut or brain. Data from international studies suggests that the
risk of serious bleeds is about 3 in 100 children and the risk of brain
bleeds is about 1 in 300 children. These bleeds most often occurred in
the first week of ITP and were often caused by a rare pre-existing abnormality
of the blood vessels in the head. The risk of serious bleeding is much
lower when the platelet count recovers to over 20 x 109/l.
What causes ITP?
ITP commonly results due to the immune system mistaking platelets
as being foreign and attacking the platelets. In many cases this may follow
a viral infection or vaccination during which time the immune system attacks
the virus but the immune system then goes on to think that the platelets
are viral material and starts to attack the platelets.
How is ITP diagnosed?
ITP is usually diagnosed using a blood test called a ‘full blood
count’. When a sample of your child’s blood is examined under a microscope,
a haematologist can examine each blood cell type closely. This is to rule
out other conditions that may cause similar symptoms to ITP. If the platelets,
red blood cells and white blood cells all look normal, this rules out
leukaemia. If the low platelet count improves quickly and no treatment
is needed, your child will not need any further tests.
If the platelet count is not showing signs of recovery by 3 to 6 months
then a small sample of bone marrow will need to be taken and examined
under the microscope. Additional blood tests may be taken at this time
to exclude rare clotting or immune diseases that can mimic ITP. If the
bone marrow looks normal, with the usual or higher number of platelet
parent cells (megakaryocytes) and other blood tests are normal then the
doctor will diagnose chronic ITP.
What is the outlook for children with ITP?
Many children, particularly younger ones, suddenly improve within
six weeks, whether or not treatment has been given. Three out of four
children will have improved by 6 months after the start of ITP. Even those
who fail to recover completely will reach a platelet count over 20 x 109/l
and have fewer bleeding problems. After six months about 25% of children
will fully recover over the following year and over half will recover
over several years.
When ITP recovers about one in 20 children will have a further occurrence
in the future.
How is ITP treated?
Most children do not need any treatment unless they have severe bleeding,
and most children improve whether or not treatment is given. The type
of treatment recommended depends on your child’s symptoms rather than
their platelet count. All the various forms of treatment aim to temporarily
improve the platelet count and do not cure the condition itself. When
treatments are considered, you will have the chance to discuss the risks
and benefits of these, as opposed to no treatment, with the doctor. The
options for treating ITP include:
1) No treatment
The majority of children with ITP have a low platelet count but do
not have dangerous bleeding. If severe bleeding is not present at the
time of diagnosis then it is very rare for dangerous bleeding to develop
later. Without treatment most children will have a platelet count >
20 x109/l within 5 days and a normal platelet count by six
2) Tranexamic acid
Tranexamic acid does not increase the platelet count but does help
the blood to produce clots. It is particularly useful for gum bleeds,
nose bleeds or heavy periods and helps the blood to form clots without
altering the platelet count. It is best taken as a liquid ("swish
and swallow") three times per day. It most not be used if there
is any blood in the urine.
3) Steroid treatment
Steroids are sometimes given to children with ITP on a short-term basis
in an attempt to increase their platelet count. However, when the steroid
dose is reduced, the platelet count will drop again after a few days.
Steroids should only be given for a short period of between 4 to 7 days.
Side effects such as weight gain and mood changes are common. Longer
courses of steroids may dampen the immune system, weaken bones, cause
diabetes or obesity and stunt growth.
3) Intravenous immunoglobulin
Immunoglobulins are antibodies which can reduce platelet destruction.
They are a blood product produced from many donors and have a theoretical
but very low risk of transmitting blood-borne infections. One course
of treatment with immunoglobulin takes two to five days as an in-patient
in the hospital and the benefit will usually last about a month. Side
effects such as fever and headaches are common.
4) Anti – D (WinRho)
WinRho can be used in Rhesus positive children (about 85% of children).
WinRho is similar to immunoglobulin in producing antibodies which the
immune system targets rather than the platelets. Anti-D is also a blood
product but produced from a small number of donors. A small drop in
the haemoglobin is common, rarely (1 in 40000 recipients) a severe and
dangerous drop in the haemoglobin is seen. Anti-D can be given as a
day case over about ten minutes and the benefit may last for several
In ITP the majority of platelets are destroyed in the spleen. Removing
the spleen (splenectomy) is often effective
in preventing early destruction of the platelets and allows the count
to rise. In children however this is rarely necessary unless the ITP
persists and the child has recurrent severe bleeds. Splenectomy is a
major surgical procedure and carries a long term risk of severe infection.
What about school, sport and holidays?
Most severe bleeds tend to occur in the first week and in children
with a platelet count under 20 x109/l. In those children with
a count over 20 x109/l they can return to school immediately
after the head teacher has been informed about the ITP. In children with
a lower platelet count school can resume after the first week and when
the school have been informed. For primary school aged children it may
be best if they take breaks inside if these can not be supervised. The
ITP Support Association produces a document for schools, clubs and playgroups.
If your child is on steroids and has not had chicken pox then school
will need to inform you if anyone in your child’s class/nursery comes
down with chicken pox.
At home it is best to take sensible precautions which all children should
follow such only cycling with a helmet and if swimming no diving into
the shallow end! It is sensible to avoid sports where there is a risk
of head injury whilst the platelet count is below 50 x109/l.
Make sure any sports teachers are aware. With a platelet count between
50 and 100 x109/l there will still be more bruising so encourage
the use of shin pads etc. For further details discuss with your consultant.
It is best not to take any holidays abroad in the first three months
of ITP as it may be difficult to get insurance. After this time most cases
of ITP will have resolved. If the ITP does persist you will need to discuss
further with your doctor and you will need specialist medical insurance.
A list of recommended insurance companies can be obtained from ITP Support
Association (details below)
What else can I do?
Your child should also avoid drugs like aspirin, ibuprofen or herbal
medication which can increase the risk of bruising and bleeding. Finally,
you should make sure that doctors and dentists know that your child has
a low platelet count if they are due to have an operation.
When to seek help?
When your child is sent home you will be given a clinic appointment
for review at the hospital and an emergency number (usually the phone
number to the children’s ward). You should contact the hospital in the
- A prolonged (over 30 minutes) nosebleed which will not stop despite
pinching the nose
- Prolonged gum bleeding
- Blood in the poo or urine
- Following a heavy blow to the head, particularly if the child is stunned
- Persistent or severe headache
- Vomiting or drowsiness
- Children on steroids are at a greater risk of a severe form of chickenpox.
If your child has not had chicken pox then contact the hospital If your
child is in direct contact with someone who has chicken pox or who develops
chickenpox within 7 days of being with your child.
Is there a UK registry?
To maintain accurate numbers of cases of childhood ITP and investigate
possible markers for risk of severe bleeding a UK registry has been established
Families may be routinely asked to consent for anonymous data to be stored
on the registry.
Information about the MMR vaccine.