essentials of tuberculosis in children , essentials of tuberculosis in children , کتابخانه دیجیتالی دانشگاه علوم پزشکی و خدمات درمانی شهید بهشتی

As children acquire infection with Mycobacterium tuberculosis from adults in their environment, the epidemiology of childhood tuberculosis (TB) follows that in adults. While global burden of childhood tuberculosis is unclear, in developing countries the annual risk of tuberculosis infection in children is 2- 5 per cent. Nearly 8-20 per cent of the deaths caused by tuberculosis occur in children. It has been suggested that BCG vaccination is responsible for decrease in the occurrence of disseminated and severe disease. Localized forms of illness, e.g., intrathoracic lymphadenopathy, and localized CNS disease have been reported to occur with greater frequency in vaccinated children. Human immunodeficiency virus (HIV) infected children are at an increased risk of tuberculosis, particularly disseminated disease. Diagnosis of TB in children presents special problems as the sputum is generally not available for examination. Diagnostic algorithms include scoring system utilizing clinical parameters and results of investigations. Various diagnostic techniques such as improved culture techniques, serodiagnosis, and nucleic acid amplification have been developed and evaluated to improve diagnosis of childhood tuberculosis. Serodiagnosis is an attractive investigation but till date none of the tests showed desirable sensitivity and specificity. Tests based on nucleic acid amplification are a promising development. Relatively less experience in children, need for technical expertise and high cost are the limiting factors for their use in childhood tuberculosis. Short-course chemotherapy for childhood tuberculosis is well established. Treatment with intermittent regimens is comparable to daily regimens. Directly observed treatment strategy (DOTS) has also shown encouraging results. Pattern of drug resistance among children with TB tends to reflect those found among adults in the same population. The rates of drug resistance to any drug vary from 20 to 80 per cent in different geographic regions.

Several changes have been observed in the epidemiology, clinical manifestations, diagnostic modalities and treatment of tuberculosis. Emergence of HIV epidemic and drug resistance have posed significant challenges. With increase in number of diseased adults and spread of HIV infection, the infection rates in children are likely to increase. It is estimated that in developing countries the annual risk of tuberculosis infection in children is 2.5%. Nearly 8-20% of the deaths caused by tuberculosis occur in children. Lymph node tuberculosis has increased over last two decades. HIV infected children are at an increased risk of tuberculosis, particularly disseminated disease. In last two decades drug resistant tuberculosis has increased gradually. The rates of drug resistance to any drug varied from 20% to 80% in different geographic regions. Various diagnostic techniques such as improved culture techniques, serodiagnosis, and nucleic acid amplification have been developed and evaluated to improve diagnosis of childhood tuberculosis. Serodiagnosis is an attractive investigation but till date none of the tests have desirable sensitivity and specificity. Tests based on nucleic acid amplification are a promising advance. Relatively less experience in children, need for technical expertise and high cost are limiting factors for their use in children with tuberculosis. Short-course chemotherapy for childhood tuberculosis is well established. Treatment with intermittent regimens is comparable to daily regimens. Directly observed treatment strategy have shown encouraging result.

BACKGROUND:The prophylactic agent ketotifen has been studied in mild-to-moderate asthma. Various trials showed benefit from 10 to 12 weeks of therapy, but no trial in children with followup beyond 12 weeks of the drug is available.OBJECTIVES:We studied the efficacy of ketotifen, 1 mg twice a day, orally as a prophylactic drug in children with asthma.METHODS:The double-blind, placebo-controlled trial studied 120 asthmatic children of either sex between the ages of 5 to 15 years at a tertiary care hospital. After an observation period of 4 weeks, children were randomly assigned to receive either ketotifen, 1 mg twice a day, or placebo for 6 months. Antiasthma drugs were continued as required. Main outcome measures included average duration for regular antiasthma drugs, average symptom scores, symptom free days, peak expiratory flow rate, FEV1, and need for emergency room visits.RESULTS:Of the 120 children enrolled, 13 could not complete the trial. Thus 58 children remained in the treatment group and 49 were in the placebo group. Both groups were comparable in their baseline characteristics. The average number of days that required antiasthma drugs were significantly less in the treatment group: salbutamol (27+/-4.7 versus 37+/-3.5 P < .05), theophylline (37+/-4.7 versus 51+/-4.8 P < .05), oral steroids (2+/-0.4 versus 5+/-1.6 P < .05), and inhalation steroids (18+/-2.7 versus 16+/-10.8 P < .05). The average symptom scores and symptom free days for cough, wheeze, and breathlessness also favored the ketotifen group. Emergency room visits were also significantly lower in the ketotifen group (20 versus 10 P < .05). Statistically significant improvement in all the above parameters were observed after 14 weeks of therapy. The mean PEFR, FEV1 and side effects of medications were comparable between the two groups.CONCLUSIONS:Ketotifen, 1 mg twice a day, is an effective prophylaxis for asthma in children between 5 to 15 years. Significant clinical improvement is evident after 14 weeks of therapy.

OBJECTIVE:To study the role of various factors associated with development and severity of bronchial asthma in children between 5-15 years of age.SETTING:Tertiary Care Medical College Hospital.METHODS:A case control study was carried out during May 96 to April 98. Sixty children each suffering from mild (chronic) and severe asthma (chronic) and 60 controls were enrolled to study the association of various risk factors with development of asthma and for severe disease.RESULTS:On univariate analysis factors associated with significant risk for development of asthma included family history of asthma (p = 0.003), lack of exclusive breastfeeding (p = 0.05), past history of bronchiolitis (p = 0.02), associated allergic rhinitis (p = 0.04) and atopic dermatitis (p = 0.01). For development of severe asthma, associated factors were early onset of symptoms (p = 0.01), family history of asthma in grandparents (p = 0.04) and more than 10 cigarettes per day smoked by any family member. No significant effect of air pollution, overcrowding, pets and passive smoking were found on either development of asthma or it's severity. On multivariate analysis only age of onset below 48 months was associated with severe asthma (OR 2.13, 95% CI 1.00-4.54). Exclusive breastfeeding for more than 4 months was the most protective factor for development of asthma (OR 0.25, 95% CI 0.08-0.70). A strong association between development of asthma and past history of bronchiolitis or tuberculosis (OR 5.26, 95% CI 1.7-16.20) and presence of associated atopic dermatitis or rhinitis (OR 7.5, 95% CI 1.64-34.48) was observed.CONCLUSION:History of associated allergic diseases and past history of bronchiolitis were significantly associated with development of asthma. Exclusive breastfeeding for first 4 months of life was protective. The most significant factor associated with severe asthma was onset of illness before 48 months of age. There was no significant effect of air pollution, over crowding, pets at home or passive smoking on severity of asthma

Diagnosis of tuberculosis in children is usually based on clinical signs and symptoms, chest roentgenogram, tuberculin testing and history of contact with adult patients. The diagnostic tests for tuberculosis can be broadly divided into 2 groups: demonstration/isolation of Mycobacterium tuberculosis or one of its components [Ziehl Neelson (ZN) staining, special stains, cultures, polymerase chain reaction]; demonstration of host's response to exposure to M. tuberculosis (Mantoux test, serodiagnosis). The yield of tests used for demonstration of mycobacterium or its components is poor because of pauci-bacillary nature of disease in children. Diagnostic use of PCR is still experimental. Serodiagnosis does not have acceptable sensitivity and specificity hence, at present, does not have any role in diagnosis of tuberculosis in children. The diagnosis is suspected on history and a combination of imaging studies and Mantoux test still remains the most widely used investigation.

An epidemic of dengue haemorrhagic fever (DHF) occurred in Delhi in 1996. A total of 240 children between the age of 4 months to 13 years of either sex, admitted in one hospital, were evaluated. Two hundred and sixteen (90%) children were from Delhi. A clinical diagnosis of dengue fever (DF) was made in 25 (10%), dengue fever with unusual bleeding (DFB) in 22 (9%), DHF in 80 (33%) and dengue shock syndrome (DSS) in 113 (47%) of the children strictly according to the WHO classification. The age peaked at 8 years. There was no association between various grades of severity of illness and age-groups though girls suffered from more severe illness. No association between severity of malnutrition and severity of illness was observed. Tourniquet test was positive in 40% with DF, 18% with DFB, 62% with DHF and 64% with DSS. In DSS haematemesis was present in 55 (49%), epistaxis in 39 (35%), melaena in 27 (24%) and ecchymosis in 34 (30%) patients. Children diagnosed as DFB had haematemesis and epistaxis in 12 (55%) and 10 (45%) respectively. Intravenous fluid requirement was clearly less in DFB patients than in DHF/DSS patients. Unusual clinical features in the form of jaundice were present in 7 (6%), hepatic encephalopathy in 6 (5%) and dengue encephalopathy in 6 (5%) patients. Dengue 2 virus was isolated from 10 of the 50 patients for whom viral culture was done on C6/36 clone of Aedes albopictus cell line. Eighteen patients suffering from DSS died giving an overall case fatality of 7.5%. The mortality rate in DHF/DSS was 9.3%. It is further suggested that DFB is a distinct entity. Most patients could be classified by the WHO classification if a retrospective packed cell volume was used to assess haemoconcentration. We suggest that development of area-specific criteria for diagnosis and management is desirable.

Dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) are life threatening clinical manifestations of infec-tion due to dengue virus. The clinical fea-tures of DHF/DSS are due to bleeding diathesis and increased capillary leak(l). The mechanisms of hemorrhagic manifes-tations in DHF/DSS are not well under-stood. The suggested factors contributing to bleeding include thrombocytopenia, coagulopathy and vasculopathy(2). Sug-gested mechanisms for thrombocytopenia include maturational arrest of megakaryo-cyte production in the bone marrow(3-5), platelet destruction by the virus itself(5,6) or disseminated intravascular coagulation (DIC)(6,7).

The clinical profile of 7 children and their follow-up is described. There was female preponderance with male to female ratio of 1∶6. The median age of onset was 6 years. All the patients had skin rash, muscle weakness and abnormal enzyme profile. Muscle biopsy was performed in 6 and was abnormal in all of them. The electromyogram (EMG) was performed in 6 and was found abnormal in five. All the children responded well to corticosteroids. Two children received intravenous dexamethasone bolus and showed good response.

From a Pediatric Rheumatology Clinic 361 children diagnosed as juvenile rheumatoid arthritis (JRA) according to American Rheumatism Association-JRA criteria were studied retrospectively for their clinico-immunological profile. The mean age of onset in systemic, pauciarticular and polyarticular onset, JRA subtypes were 5.2, 6.8 and 7.2 years respectively. There was male preponderance in systemic and pauciarticular JRA. In seropositive polyarticular JRA, girls outnumbered boys. The frequency of occurence of systemic, pauciarticular and polyarticular disease was 87 (24%), 108 (30%) and 166 (46%) respectively. The systemic onset disease was dominated by extra-articular manifestations in terms of fever (100%), rash (57%), hepatomegaly (51%) and lymphadenopathy (25%). The pauci- and polyarticular illnesses were commonly dominated by joint involvement, morning stiffness, and in few patients, by extra-articular manifestations also. The joints were involved symmetrically. Most commonly involved joints in order of decreasing frequency were knee, ankle, wrist and elbow in all the subtypes. Anemia and leucocytosis were observed in majority with higher frequency in systemic onset JRA. The rheumatoid factor (RF) was present in 15% of polyarticular JRA. RF was also present in 7 and 9% of patients with pauciarticular and systemic subtypes respectively. The antinuclear antibody was positive in only 3 out of 66 patients in whom the test was carried out.