thrombocytopenia. A significant proportion will have white blood cell counts of less
than 3000/mm^3 and about 20% will have counts greater than 50,000/mm^3. The
diagnosis of leukaemia can be suspected on seeing blast cells on the blood smear
confirmed on bone marrow biopsy, which will show replacement by leukaemic
lymphoblasts. The treatment varies with the clinical risk features; children under 2
years and over 10 years with an initial white blood cell count of over 100,000/mm^3
and central nervous system involvement (leukaemic cells in the cerebrospinal fluid)
have the worst prognosis.
The basic treatment components are:
- Induction of remission. To remove abnormal cells from the blood and bone
marrow. Drugs used: vincristine and prednisone. - Prophylactic treatment to central nervous system. Drugs used: intrathecal
methotrexate plus irradiation of central nervous system. - Consolidation. Drugs used: cytosine arabinoside plus asparaginase.
- Maintenance. Drugs used: methotrexate plus mercaptopurine for approximately 2
years. - Relapse. If relapse occurs then bone marrow transplantation can be considered.
On this regimen over 70% of children now survive and can be regarded as cured.
Key Points
Childhood leukaemia:
- 75% is acute lymphocytic leukaemia;
- peak incidence at 4 years of age;
- dentists can help early diagnosis, alerted by mucosal haemorrhage, and mouth and
throat infections.
Dental management of leukaemia
In common with other medically compromising conditions, children with leukaemia
are categorized as having a high risk of dental caries. Therefore, prevention is
essential. Unless there is a dental emergency no elective operative dental treatment
should be carried out until the child is in remission. The drug regimen used to induce
remission has numerous side-effects, including nausea and vomiting, reversible
alopecia (hair loss), neuropathy, and, most importantly from a dental point of view,
oral ulceration (mucositis). It can be extremely difficult to carry out normal mouth
care for children at this stage and many have difficulty with toothbrushing due to
acute nausea. Swabbing the mouth with chlorhexidine mouthwash and the routine use
of antifungal agents are essential. Local anaesthesia preparations such as 5%
lignocaine (lidocaine) ointment, 20% flavoured benzocaine, or benzydamine
hydrochloride (Difflam) applied before mealtimes can help to reduce the pain from
ulceration or mucositis. The use of antibiotic paste or pastilles and ice chips can also
be helpful. Once the leukaemia is in remission, and after consultation with the child's
physician, routine dental care can be undertaken with the following adjustments: