Starting with this 17th issue I have the privilege to take over as the editor for KidTalk and I am looking forward to working with you. The outstanding contributions by our pediatric faculty have made KidTalk so successful. In order to serve your needs best, I would like to encourage all readers and contributors to come forward with comments or suggestions for future issues. It is my intention to continue Dr. Ardinger's legacy with the help of Pat Quinlan, who has taken over from Jan Black. I look forward to hearing from you.
Pediatric Critical Care;
Program Director, Combined Medicine/Pediatrics Residency.
As we begin the new millennium, the department looks forward to further growth and service to the community. We are just completing a busy recruitment season for housestaff including both pediatric and medicine-pediatric positions. We have had outstanding applicants both from the region and elsewhere. We also are expanding our pediatric faculty, particularly in neurology, neonatology and gastroenterology.
Our Annual Spring CME program, " Issues for Pediatricians and Other Health Care Professionals", will be held on May 5, 2000. Please mark the date and plan to attend. Registration forms will be mailed soon. If you need additional information, please call 913-588-6339. Hope to see you there.
Sincerely,
Professor and Chair
The American Academy of Pediatrics recommended routine varicella (chickenpox) vaccination in 1995. However, many susceptible children remain unvaccinated (approximately 34% in 1997-98), and the disease continues to occur in the United States (Pediatrics 2000; 15:136-141). The reasons for under-utilization of varicella vaccine are many, including a perception that chickenpox is a mild disease, and concerns about vaccine efficacy, durability of immunity, unwanted consequences, and insurance coverage. This brief update attempts to address some of the concerns and questions.
Chickenpox: Chickenpox is not a mild childhood annoyance. It is a highly contagious disease resulting in an excessive number of hospitalizations (approximately one of every 164 persons with varicella) and causing approximately 100 deaths per year in the United States. Varicella is a major risk for severe invasive group A streptococcal disease and an important contributor to direct medical and indirect societal costs.
Vaccine efficacy: Varicella vaccine (Oka strain) is an attenuated live virus. A single subcutaneous injection results in a seroconversion rate of over 97% in healthy children aged 12 months to 12 years, and approximately 80% in persons 13 years and older. Two doses (separated by one to two months) are needed for children 13 years and older (99% seroconversion rate). Varicella vaccine is very effective for preventing varicella infection (70 - 90%) and preventing severe disease (95 - 100%).
Duration of immunity: Studies in Japan indicate that antibodies to varicella-zoster virus (VZV) can be detected as long as 20 years after varicella vaccination. In the years following vaccination, antibody levels do not wane nor does the rate of infection increase. Follow-up studies in the United States are needed to determine whether additional doses of vaccination are needed here.
Post-exposure immunization: Recent studies indicate that vaccination after exposure to varicella is about 90% effective if done within 3 days, and possibly even within 5 days of household or hospital exposure to chickenpox. The American Academy of Pediatrics (2000) now recommends post-exposure immunization (not recommended in 1997 "Red Book"). If vaccine is given after exposure, parents should be informed regarding the 10% risk of varicella occurring under such conditions. For hospitalized patients exposed to varicella, use of vaccine, varicella-zoster immune globulin (VZIG), or antiviral agents must be individualized based on underlying immune status.
Vaccine-associated rashes: Approximately 6 - 10% of susceptible varicella vaccinees develop a mild vaccine-associated maculopapular or vesicular rash, one half with localized rash, the other half with generalized rash. These rashes, typically maculopapular rather than vesicular, occur 5 to 26 days after vaccination. It has been demonstrated that varicella-like rashes occurring within two weeks of vaccination are most likely due to coincidental infection by wild-type VZV. Varicella vaccine virus has been isolated from vaccinees with varicella-like rashes. The spread of vaccine virus from these individuals to others occurs infrequently (less than 1%).
Herpes zoster after vaccination: Herpes zoster has been observed in recipients of varicella vaccine. Post-licensure surveillance suggests that the incidence of herpes zoster is higher in natural infection than in vaccine immunized persons (68 Vs 2.6 per 100,000 person-years).
Chief, Pediatric Infectious Diseases.
The prognosis for young people with lupus is better than ever today, but much depends on early diagnosis and appropriate long-term treatment
SLE is the second most common rheumatic disease of childhood and one fifth of all patients with SLE experience onset of the disease in childhood.
SLE’s clinical manifestations result from inflammatory changes induced by the deposition of immune complexes in tissue. The disease is believed to involve the interaction of genetic, hormonal, and environmental influences.
SLE should be considered in any child, particularly a female, who presents with a prolonged or recurrent febrile illness with evidence of multisystem involvement. The most common presenting findings are rash, arthritis and renal disease associated with leukopenia and a positive antinuclear antibody (ANA). These findings may occur singly or in combination, and the entire clinical picture may not be evident for several years. In the majority of patients however, two years is adequate for the disease to declare itself.
Complete Blood Count. A normocytic,
normochromic anemia (hemoglobin less than 10 g/dL) is present in up to
70% of patients. Coombs’ antibodies are also common but result in
a hemolytic anemia in only 5% of patients.
Leukopenia (white cell count of less than 4,000/m L), including lymphopenia,
occurs in about half of patients and is an indicator of active disease. White
cell counts of less than 1,500/m L are uncommon and may be associated with
leukocytotoxic antibodies.
Thrombocytopenia (platelets less than 150,000/m L) is common but counts below 100,000 occur in only about 5% of patients. Both immune thrombocytopenic purpura and thrombotic thrombocytopenic purpura may be associated with SLE and may even be the presenting manifestation.
Acute-phase reactants. The erythrocyte sedimentation rate is elevated in the majority of children with active lupus, especially early in the course. C-reactive protein levels do not correspond and often remain normal.
Autoantibodies. Hundreds of different autoantibodies have been identified; some correspond to subtypes of SLE or identify certain risks. Antinuclear antibodies are present in more than 95% of young people with SLE, and the test is valuable for screening symptomatic patients. Titers may be low in children, especially early in the disease, and do not correspond to the severity of disease. ANA titers change slowly and thus are not good indicators of disease activity.
Test results also may vary according to the substrate used. Of the four staining patterns reported for liver or kidney substrates, (speckled, homogenous, rim and nucleolar) a diffuse, homogeneous pattern is most commonly associated with SLE.
Antibodies to double-stranded DNA or nDNA are present in the majority of patients with nephritis, but rarely in other childhood rheumatic disease. The sensitivity of the test for detecting disease activity varies with individual patients and the assay method. The commonly used Crithidia Lucille immunofluorescent test is relatively insensitive and thus may not be helpful for screening purposes or early in disease.
Complement and immunoglobulins. Serum complement determinations, either total hemolytic complement (CH50) or the individual protein components C3 and C4 are the most sensitive indicators of active disease routinely available. They reflect activation of the complement cascade by the formation of immune complexes, except in hereditary complement component deficiency. A marked, polyclonal hypergammaglobulinemia is common.
The American College of Rheumatology criteria for SLE were established to provide uniformity for studies and communications regarding SLE, but they are also used in diagnosis. The presence of four or more criteria is adequate for the diagnosis of SLE with a high degree of specificity.
The differential diagnosis in children includes other rheumatic diseases, especially juvenile rheumatoid arthritis and juvenile dermatomyositis. When joint symptoms are the predominant complaint, particularly in an adolescent girl, several months may be necessary to differentiate the JRA from SLE. Evidence of multisystem involvement is the key factor distinguishing SLE. In juvenile dermatomyositis, the main problem is severe muscle weakness associated with elevation of muscle enzymes, not a common finding in childhood lupus. Mixed connective tissue disease is considered a variant of SLE, characterized by arthritis, sclerodactyly, and myositis.
All of the above diseases are associated with a positive ANA in a percentage of patients, but other autoantibodies are more common in SLE. Other diseases to consider include atypical infections, especially Epstein-Barr viral disease, and malignancies.
Chair, Department of Pediatrics;
Division Chief, Pediatric Rheumatology.
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