Most cases of idiopathic thrombocytopenic purpura (ITP) in children recover completely. Only 10-20% cases take a chronic course, i.e., thrombocytopenia persists beyond six months after the onset(1). While there is consensus that bleeding related symptoms and not only the platelet count should be the basis of treatment of chronic ITP (CITP), the consensus on which therapy to be used has not yet emerged(2). Splenectomy is regarded as effective in as many as 50-70% patients but is generally avoided in children younger than 5 years(1,3). Other therapy including IVIG administration are either very expensive or do not produce consistent results(4).

Anderson reported complete response in all his 10 patients of CITP with oral high dose dexamethasone (HDD) used in pulsed manner(4). Other studies with HDD have not shown such consistency of results(5,6). We used this form of therapy initially in a patient of acute ITP refractory to prednisolone, methylprednisolone and IVIG therapy. He showed a brisk increase in platelet count which was sustained. Subsequently we used HDD in CITP, the results of which are reported.

This prospective study was conducted on children with CITP under 12 years of age. The diagnosis of CITP was based on clinical history of mucocutaneous bleeding, thrombocytopenia (platelet count less than 150 ´ 109/L) and normal or increased megakaryocytes on bone marrow examination. Informed consent was obtained from the parents on behalf of the children participating in the study.

Patients were administered dexamethasone intravenously in a single daily dose of 25 mg/M2 on 4 consecutive days. The cycles were repeated every 28 days for 6 cycles. Complete blood counts were done on first and 5th day of the cycle and then every 2 weeks. Patients’ bleeding manifestations, weight and blood pressure were recorded regularly.

A successful short term response was defined as platelet count 50 ´ 109/L or more on day five of each cycle with absence of spontaneous bleeding. Long term response was assessed 6 months after completion of therapy and was defined as absence of bleeding manifestations and platelet count 100´ 109/L or more.

The mean age of the patients was 5 years (range 1.5-8 years) and the mean duration of disease was 17.3 months (range 8-36 months). There were 7 boys and 2 girls (Table I). All children had significant bleeding manifesta-tions. All children had received one or more courses of prednisolone while 1 case had received methyl prednisolone (30 mg/kg/day for 3 days). Two patients were lost to follow up after one and 5 courses and thus were available only for short term response. One patient (Patient No. 6) received only 5 courses.

Platelet count at study entry ranged between 4-37 ´ 109/L. Short term response in first through sixth cycle was seen in 55.5%, 62.5%, 62.5%, 75%, 50% and 57.1%. patients, respectively. Overall short term response was seen in 60.4% courses. Long term response was seen in 3 of the 7 (40.0%) cases, one of these cases had thrombocytopenia three months after sixth course, and needed one more cycle. These three cases are now asymptomatic and are maintaining platelet count above 150 ´ 109/L for 13-21 months follow up.

Table I: Characteristics of the Patients and Response to Therapy

Since the first report in 1994, HDD for CITP has been used by various workers with response rates ranging from 0-40%(4,6-8). Use of HDD in pediatric age group has also yielded almost similar results(5,9,10). In our series of 9 patients short term response was observed in 60% courses while Kuhne et al. reported short term response in 78% courses(10). We observed an increase in the platelet count above 100 ´ 109/L in 3 (40.8%) cases which is sustained. Though this can at best be described as a moderate response rate, this form of therapy has an appeal of being well tolerated and inexpensive(6). Moreover various other forms of therapy, e.g., vinca alkaloids and danazol have shown similar response rates(1,11,12).

Corticosteroids have multiple effects on reticuloendothelial system that could lead to an increased platelet count in ITP, including interference with platelet antigen-antibody interactions, diminished Fc receptor mediated platelet clearance and suppression of auto-antibody production(13). Dexamethasone also has a direct lympholytic effect, triggers apoptosis of lymphocytes, inhibits T cell activation, suppresses B-cell differentation and regulates Fc receptors of macrophages(14). Although the daily dose of dexamethasone was very high, no significant side effects were noted. Single daily dose is important for minimizing side effects as has been previously recommended for high dose methyl predni-solone therapy. The usual tablet of dexa-methasone available in Indian market is 0.5 mg. This would have necessitated swallowing of a large number of tablets by very young children. Hence we used an intravenous preparation of dexamethasone. However, currently we are using oral dexamethasone and this is being tolerated well by children.

Our observation based on small number of patients suggests that HDD has a moderate success in patients with CITP. As it is inexpensive and well tolerated regimen, it may be used as a modality of treatment in children before resorting to splenectomy and other expensive therapies.

Contributors: JC coordinated the study (its design and data interpretation) and drafted the paper; he will act as guarantor for the article. TD helped in data collection and drafting the paper. SN helped in drafting the paper. VJ and SS helped in data collection. AKD helped in drafting the paper and critically evaluating the manuscript.
Funding: None.
Competing interests: None stated.

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