From Medscape Medical News
Laurie Barclay, MD
October 29, 2009 — Whether yearly vaccinations for children against seasonal influenza might stop immunity developing against pandemic strains is debated in a personal view and reflection and reaction published online October 30 and will appear in the December print edition of The Lancet Infectious Diseases.
"Yearly vaccination is necessary because of the substantial antigenic drift of influenza viruses that necessitates the update of vaccines every year...driven by selective pressure mediated by antibodies induced by natural infection or vaccination," write Rogier Bodewes, DVM; Joost H.C.M. Kreijtz, PhD; and Guus F. Rimmelzwaan, PhD, from Erasmus Medical Center in Rotterdam, The Netherlands.
"The vaccination of healthy children aged 6–59 months against seasonal influenza has been recommended in several countries, including the USA and some European countries," the authors continue, "because the disease is an important cause of illness and admission to hospital in this age group. Although annual vaccination against seasonal influenza is beneficial for all patients at high risk, including children, vaccination of the 6–59 month age group every year against seasonal influenza might have a downside that has not been given much thought."
Previous studies, mostly in mice and other animals, have shown that infection with influenza A viruses can induce heterosubtypic immunity, which is protective immunity to influenza A viruses of other unrelated subtypes. Although heterosubtypic immunity does not offer full protection, it can limit virus replication and reduce influenza symptoms and mortality in the host.
The authors note that the ramifications of heterosubtypic immunity should be considered in humans when a new subtype of influenza A virus is introduced into the population. Pertinent examples include the novel influenza A H1N1 virus causing the present influenza pandemic and the highly pathogenic avian influenza H5N1 viruses responsible for increasing numbers of human infections, which are often fatal.
The authors suggest that an untoward effect of preventing infection with seasonal influenza viruses by vaccination might be to prevent the induction of heterosubtypic immunity to pandemic strains. Infants and other immunologically naive individuals would be at greatest risk were this to occur.
To test their theory, the authors suggest that hospitalizations and mortality rates among infants who have received yearly influenza vaccination since birth should be closely monitored and compared with those in age-matched children who were not vaccinated. The present H1N1 pandemic offers a unique opportunity to investigate heterosubtypic immunity and to determine potential harms of annual influenza vaccination.
In the meantime, the authors support the current vaccination program against H1N1 influenza and acknowledge that it will decrease morbidity and deaths in all age groups.
"Use of these pandemic influenza vaccines will override the theoretical issues associated with yearly vaccination against seasonal influenza," the study authors conclude. "The development and use of vaccines that can induce broad protective immunity might be a solution for these potential problems and we think this is a priority."
In an accompanying reflection and reaction, Terho Heikkinen, MD, and Ville Peltola, MD, from Turku University Hospital in Finland, argue that prevention of seasonal influenza in children by vaccination far outweighs the theoretical risk of preventing the induction of heterosubtypic immunity to pandemic strains. However, they agree with Dr. Bodewes and colleagues that more effective influenza vaccines that could induce broader immune responses are needed.
"The results of experimental animal studies can never be extrapolated directly to human beings, let alone form the basis of any vaccination policy," Dr. Heikkinen and Dr. Peltola write. "There is ample evidence for the great burden of influenza in young children, and this burden appears during every influenza season. By contrast, there is no clinical evidence that vaccinating children against influenza would prevent the induction of heterosubtypic immunity and thereby be disadvantageous to children in the long run."
Dr. Heikkinen and Dr. Peltola therefore advocate continuing the ongoing influenza vaccination program.
"While waiting for improved influenza vaccines, the simple question is should we let young children suffer from a severe and potentially lethal but easily preventable illness, just because there is a theoretical possibility that withholding vaccination might result in a slightly less severe illness sometime in the future?" they conclude. "We believe that the answer to this question is a simple one."
Dr. Rimmelzwaan is a consultant to Viroclinics BV. The other 2 personal view authors have disclosed no relevant financial relationships. Dr. Heikkinen has provided consultancy services to Novartis, Medimmune, GlaxoSmithKline, and Solvay. Dr. Peltola has received grants from GlaxoSmithKline and provided consultancy services to Novartis.
Lancet Infect Dis. Published online October 30, 2009.
Friday, October 30, 2009
Melamine contamination of formula milk and urinary tract stones
Melamine increases the apparent protein content of foods because of its high nitrogen content. This was probably the reason behind the recent contamination of infant formula milks with melamine in China. Researchers in Beijing have reported their findings in 589 children screened for urinary tract stones after possible exposure to melamine-contaminated formula milk.
Of 589 children aged up to 36 months examined, 421 had received contaminated formula. On ultrasonography, 50 children had definite urinary tract stones. Eight of these had not been given the melamine-containing formula. One hundred and twelve had suspected stones and 427 no stones. Children with stones, suspected stones and no stones were equally likely to have haematuria (6%) or pyuria (3%). Glomerular function was abnormal in 10% of children with stones. Children given a high-melamine formula had a sevenfold increase in risk of stones. Prematurity was also associated with increased risk of stones. Further data are provided from Hong Kong and Taiwan in letters to the editor.
Melamine-contaminated formula increased the risk of renal tract stones.
Guan N, et al. Melamine-contaminated powdered formula and urolithiasis in young children. NEJM 2009;360:1067–1074; Langman CB. Melamine, powdered milk, and nephrolithiasis in Chinese infants. Ibid: 1139–1141 (editorial); Ho SSY, et al. Ultrasonographic evaluation of melamine-exposed children in Hong Kong. Ibid: 1156–1157 (letter); Wang I-J, et al. Melamine and nephrolithiasis in children in Taiwan. Ibid: 1157–1158 (letter).
http://www.mims.com/Page.aspx?menuid=RecentHL&RecentHeaderID=355
Of 589 children aged up to 36 months examined, 421 had received contaminated formula. On ultrasonography, 50 children had definite urinary tract stones. Eight of these had not been given the melamine-containing formula. One hundred and twelve had suspected stones and 427 no stones. Children with stones, suspected stones and no stones were equally likely to have haematuria (6%) or pyuria (3%). Glomerular function was abnormal in 10% of children with stones. Children given a high-melamine formula had a sevenfold increase in risk of stones. Prematurity was also associated with increased risk of stones. Further data are provided from Hong Kong and Taiwan in letters to the editor.
Melamine-contaminated formula increased the risk of renal tract stones.
Guan N, et al. Melamine-contaminated powdered formula and urolithiasis in young children. NEJM 2009;360:1067–1074; Langman CB. Melamine, powdered milk, and nephrolithiasis in Chinese infants. Ibid: 1139–1141 (editorial); Ho SSY, et al. Ultrasonographic evaluation of melamine-exposed children in Hong Kong. Ibid: 1156–1157 (letter); Wang I-J, et al. Melamine and nephrolithiasis in children in Taiwan. Ibid: 1157–1158 (letter).
http://www.mims.com/Page.aspx?menuid=RecentHL&RecentHeaderID=355
Epinephrine and dexamethasone for viral wheeze in infants
There is uncertainty about the value of inhaled bronchodilators and steroids for infants who wheeze. Now a multicentre trial in Canada has shown that treatment with oral dexamethasone and inhaled epinephrine (adrenaline) in the emergency department reduced rates of hospital admission.
The trial was carried out at eight centres during December to April in 2004–2007. A total of 800 infants aged 6 weeks–12 months (median age, 5 months) with a diagnosis of acute bronchiolitis (defined as a first episode of wheezing associated with signs of an upper respiratory tract infection during the peak respiratory syncytial virus season) were randomized to four treatment groups in the emergency department: epinephrine plus dexamethasone (ED), epinephrine plus placebo (EP), dexamethasone plus placebo (DP), and double placebo (PP). Epinephrine was given as two doses each of 3 mL of 1:1,000 solution via a nebulizer. Dexamethasone was given orally in an initial dose of 1 mg/kg followed by five doses of 0.6 mg/kg at 24hour intervals. Rates of hospital admission by day 7 were 17% (ED), 24% (EP), 26% (DP) and 26% (PP). There was a significant 35% risk reduction in the ED group, but this result became insignificant after statistical adjustment.
Giving oral dexamethasone and inhaled epinephrine to infants with viral wheeze (paediatricians in Britain might give a diagnosis of wheezy bronchitis) may reduce the need for hospital admission.
Plint AC, et al. Epinephrine and dexamethasone in children with bronchiolitis. NEJM 2009;360:2079–2089; Frey U, von Mutius E. The challenge of managing wheezing in infants. Ibid: 2130–2133 (editorial).
http://www.mims.com/Page.aspx?menuid=RecentHL&RecentHeaderID=363
The trial was carried out at eight centres during December to April in 2004–2007. A total of 800 infants aged 6 weeks–12 months (median age, 5 months) with a diagnosis of acute bronchiolitis (defined as a first episode of wheezing associated with signs of an upper respiratory tract infection during the peak respiratory syncytial virus season) were randomized to four treatment groups in the emergency department: epinephrine plus dexamethasone (ED), epinephrine plus placebo (EP), dexamethasone plus placebo (DP), and double placebo (PP). Epinephrine was given as two doses each of 3 mL of 1:1,000 solution via a nebulizer. Dexamethasone was given orally in an initial dose of 1 mg/kg followed by five doses of 0.6 mg/kg at 24hour intervals. Rates of hospital admission by day 7 were 17% (ED), 24% (EP), 26% (DP) and 26% (PP). There was a significant 35% risk reduction in the ED group, but this result became insignificant after statistical adjustment.
Giving oral dexamethasone and inhaled epinephrine to infants with viral wheeze (paediatricians in Britain might give a diagnosis of wheezy bronchitis) may reduce the need for hospital admission.
Plint AC, et al. Epinephrine and dexamethasone in children with bronchiolitis. NEJM 2009;360:2079–2089; Frey U, von Mutius E. The challenge of managing wheezing in infants. Ibid: 2130–2133 (editorial).
http://www.mims.com/Page.aspx?menuid=RecentHL&RecentHeaderID=363
Report of Motor Neuron Disease After HPV Vaccine
Medscape Conference Coverage, based on selected sessions at the:
American Neurological Association (ANA) 134th Annual Meeting
From Medscape Medical News
Allison Gandey
October 28, 2009 (Baltimore, Maryland) — Investigators are reporting a case of motor neuron disease after immunization with the quadrivalent vaccine Gardasil. The Merck product is designed to prevent infection with several types of human papillomavirus.
Presenting here at the 134th annual meeting of the American Neurological Association, researchers describe a case of rapidly progressive disease leading to the death of a 14-year-old girl.
Symptoms began 2 months after the last dose of Gardasil.
"Pathological features support the temporal association of the clinical presentation and vaccination and provides supporting evidence that immune-mediated reactions to the nervous system are potential risks after Gardasil vaccination," Catherine Lomen-Hoerth, MD, director of the Amyotrophic Lateral Sclerosis Center at the University of California–San Francisco, told the meeting.
"Our patient received 3 doses of Gardasil with symptom onset 2 months after her last dose," the poster presenters wrote. "Despite treatment with aggressive immunosuppression, her weakness relentlessly progressed and she died of respiratory failure 21 months after the onset of her weakness."
Postmortem evaluations revealed widespread infiltrates of T lymphocytes and macrophages in the grey and white matter at all levels of the spinal cord. Researchers also report extensive demyelination and severe loss of motor neurons.
In September, investigators presenting at the European Committee for Treatment and Research in Multiple Sclerosis annual meeting reported cases of autoimmune disorders after immunization with Gardasil.
Two groups presented at the meeting — one identified a case of multiple sclerosis after vaccination and the second a case of neuromyelitis optica.
Other Reports of Autoimmune Disorders
Presenter Maria Bouktsi from the Interbalkan European Medical Center in Thessaloniki, Greece, told Medscape Neurology that her team is questioning whether the immuno-stimulatory properties of the human papillomavirus–like particles of the vaccine are triggering adverse effects in vulnerable patients.
It is the same question that researchers asked in a recent issue of Multiple Sclerosis (2009;15:116–119). Ian Sutton, MD, from St. Vincent's Hospital in New South Wales, Australia, and his team reported 5 cases of multiple sclerosis after vaccination with the drug. The group reported in January that patients presented with multifocal or atypical demyelinating syndromes within 21 days of immunization.
No definitive conclusions can be made based on this report, Dr. Sutton and his team noted. "It should not be overlooked that several epidemiological studies indicate that viral infection is associated with a threefold increase in the risk of a multiple sclerosis relapse," write the researchers.
7 More Cases
Lead investigator of the second group presenting on this topic said that he agrees that postmarketing pharmacosurveillance is necessary to improve safety. "[Human papillomavirus] vaccines elicit a strong inflammatory systemic immune response," said Til Menge, MD, from Heinrich-Heine University in Düsseldorf, Germany.
His group suggests that it was this inflammatory response that may have triggered a case of fulminant neuromyelitis optica in a previously healthy 17-year-old girl.
Investigators have not established a causal relationship, but they are asking clinicians to closely monitor patients for any emerging side effects.
The researchers have disclosed no relevant financial relationships.
American Neurological Association 134th Annual Meeting: Poster WIP-19. Presented October 13, 2009.
American Neurological Association (ANA) 134th Annual Meeting
From Medscape Medical News
Allison Gandey
October 28, 2009 (Baltimore, Maryland) — Investigators are reporting a case of motor neuron disease after immunization with the quadrivalent vaccine Gardasil. The Merck product is designed to prevent infection with several types of human papillomavirus.
Presenting here at the 134th annual meeting of the American Neurological Association, researchers describe a case of rapidly progressive disease leading to the death of a 14-year-old girl.
Symptoms began 2 months after the last dose of Gardasil.
"Pathological features support the temporal association of the clinical presentation and vaccination and provides supporting evidence that immune-mediated reactions to the nervous system are potential risks after Gardasil vaccination," Catherine Lomen-Hoerth, MD, director of the Amyotrophic Lateral Sclerosis Center at the University of California–San Francisco, told the meeting.
"Our patient received 3 doses of Gardasil with symptom onset 2 months after her last dose," the poster presenters wrote. "Despite treatment with aggressive immunosuppression, her weakness relentlessly progressed and she died of respiratory failure 21 months after the onset of her weakness."
Postmortem evaluations revealed widespread infiltrates of T lymphocytes and macrophages in the grey and white matter at all levels of the spinal cord. Researchers also report extensive demyelination and severe loss of motor neurons.
In September, investigators presenting at the European Committee for Treatment and Research in Multiple Sclerosis annual meeting reported cases of autoimmune disorders after immunization with Gardasil.
Two groups presented at the meeting — one identified a case of multiple sclerosis after vaccination and the second a case of neuromyelitis optica.
Other Reports of Autoimmune Disorders
Presenter Maria Bouktsi from the Interbalkan European Medical Center in Thessaloniki, Greece, told Medscape Neurology that her team is questioning whether the immuno-stimulatory properties of the human papillomavirus–like particles of the vaccine are triggering adverse effects in vulnerable patients.
It is the same question that researchers asked in a recent issue of Multiple Sclerosis (2009;15:116–119). Ian Sutton, MD, from St. Vincent's Hospital in New South Wales, Australia, and his team reported 5 cases of multiple sclerosis after vaccination with the drug. The group reported in January that patients presented with multifocal or atypical demyelinating syndromes within 21 days of immunization.
No definitive conclusions can be made based on this report, Dr. Sutton and his team noted. "It should not be overlooked that several epidemiological studies indicate that viral infection is associated with a threefold increase in the risk of a multiple sclerosis relapse," write the researchers.
7 More Cases
Lead investigator of the second group presenting on this topic said that he agrees that postmarketing pharmacosurveillance is necessary to improve safety. "[Human papillomavirus] vaccines elicit a strong inflammatory systemic immune response," said Til Menge, MD, from Heinrich-Heine University in Düsseldorf, Germany.
His group suggests that it was this inflammatory response that may have triggered a case of fulminant neuromyelitis optica in a previously healthy 17-year-old girl.
Investigators have not established a causal relationship, but they are asking clinicians to closely monitor patients for any emerging side effects.
The researchers have disclosed no relevant financial relationships.
American Neurological Association 134th Annual Meeting: Poster WIP-19. Presented October 13, 2009.
Thursday, October 29, 2009
Tanning Increases Moles in Light-Skinned Children
From Medscape Dermatology > Viewpoints
Graeme M. Lipper, MD
Arch Dermatol. 2009;145:989-996
Study Summary
The association among light-skin phototypes, heavy sun exposure, and cutaneous malignant melanoma (MM) is well established.
Excessive childhood ultraviolet B exposure leads to increased MM incidence later in life.[1-3]
Known risk factors for the development of MM include: a family history of MM, the presence of dysplastic nevi (or family history of dysplastic nevus syndrome), presence of numerous melanocytic nevi, and a history of heavy sun exposure.[2-4] Because individuals with numerous melanocytic nevi are at increased risk of developing MM,[4] Aalborg and colleagues sought to determine if children with light-skin phototypes who tan are at greater risk than their nontanning peers of developing multiple nevi, and by proxy, MM later in life.
This prospective study began with a cohort of 1145 children (ages 5-6 years) recruited from the Denver metropolitan area during 2003 and 2004. Of this initial group, 696 children completed 3 consecutive annual skin examinations. Investigators further reduced this cohort by excluding patients with red hair (considered to be a genetically distinctive group with a low baseline incidence of nevi), incomplete data, or darker skin phototypes. The remaining study population was composed of 131 very light-skinned white children without red hair and 444 darker-skinned white children without red hair. Investigators followed this cohort for the development of melanocytic nevi for 3 years. Of note, skin pigmentation was objectively determined with colorimetry analysis (Chroma Meter CR-400, Konica Minolta Sensing Americas, Inc, Ramsey, New Jersey). By comparing the skin pigmentation in photoprotected (axillary) vs photoexposed (forearm) areas of skin, investigators further stratified very light-skinned children into 2 subgroups: low tanners (n = 20) and high tanners (n = 111).
During the 3-year follow-up period, Aalborg and colleagues noted the following:
Very light-skinned children who tanned had significantly more nevi develop compared with their nontanned peers.
Minimally tanned light-skinned children had mean nevus counts of 14.8 at 6 years, 18.8 at 7 years, and 22.3 at 8 years. In contrast, light-skinned children who tanned had mean nevus counts of 21.2 at 6 years, 27.9 at 7 years, and 31.9 at 8 years.
The aforementioned association was independent of variables such as the child's base skin color, hair color, eye color, parent-reported sun exposure, hours per week in the sun, sun protection behavior, past sunburns, and vacation sun exposure.
Darker-skinned white children showed no relationship between tanning and number of nevi.
Viewpoint
Are children with light-skin phototypes who tan at greater risk of developing melanoma later in life than their nontanned peers?
Previous studies have already shown that among white children, those with lighter-skin phototypes are 2-3 times more likely to have MM develop than those with darker-skin types.[3]
In addition, studies of light-skinned white children in Europe and Canada have demonstrated a clear association between a history of multiple or severe (blistering) sunburns and high nevi counts.[5,6]
Aalborg and colleagues now add to this important body of knowledge by showing that light-skinned white children who tan clearly develop a greater number of melanocytic nevi than their nontanned peers, even at an early age.
Because many MMs do not occur within existing nevi, the presence of multiple nevi in these young children likely serves as a marker for ultraviolet-induced skin damage and/or a genetic susceptibility to MM.
In this context, it seems clear that parents of light-skinned children should be educated about the benefits of photoprotecting their children to avoid tanning, starting at an early age.
Graeme M. Lipper, MD
Arch Dermatol. 2009;145:989-996
Study Summary
The association among light-skin phototypes, heavy sun exposure, and cutaneous malignant melanoma (MM) is well established.
Excessive childhood ultraviolet B exposure leads to increased MM incidence later in life.[1-3]
Known risk factors for the development of MM include: a family history of MM, the presence of dysplastic nevi (or family history of dysplastic nevus syndrome), presence of numerous melanocytic nevi, and a history of heavy sun exposure.[2-4] Because individuals with numerous melanocytic nevi are at increased risk of developing MM,[4] Aalborg and colleagues sought to determine if children with light-skin phototypes who tan are at greater risk than their nontanning peers of developing multiple nevi, and by proxy, MM later in life.
This prospective study began with a cohort of 1145 children (ages 5-6 years) recruited from the Denver metropolitan area during 2003 and 2004. Of this initial group, 696 children completed 3 consecutive annual skin examinations. Investigators further reduced this cohort by excluding patients with red hair (considered to be a genetically distinctive group with a low baseline incidence of nevi), incomplete data, or darker skin phototypes. The remaining study population was composed of 131 very light-skinned white children without red hair and 444 darker-skinned white children without red hair. Investigators followed this cohort for the development of melanocytic nevi for 3 years. Of note, skin pigmentation was objectively determined with colorimetry analysis (Chroma Meter CR-400, Konica Minolta Sensing Americas, Inc, Ramsey, New Jersey). By comparing the skin pigmentation in photoprotected (axillary) vs photoexposed (forearm) areas of skin, investigators further stratified very light-skinned children into 2 subgroups: low tanners (n = 20) and high tanners (n = 111).
During the 3-year follow-up period, Aalborg and colleagues noted the following:
Very light-skinned children who tanned had significantly more nevi develop compared with their nontanned peers.
Minimally tanned light-skinned children had mean nevus counts of 14.8 at 6 years, 18.8 at 7 years, and 22.3 at 8 years. In contrast, light-skinned children who tanned had mean nevus counts of 21.2 at 6 years, 27.9 at 7 years, and 31.9 at 8 years.
The aforementioned association was independent of variables such as the child's base skin color, hair color, eye color, parent-reported sun exposure, hours per week in the sun, sun protection behavior, past sunburns, and vacation sun exposure.
Darker-skinned white children showed no relationship between tanning and number of nevi.
Viewpoint
Are children with light-skin phototypes who tan at greater risk of developing melanoma later in life than their nontanned peers?
Previous studies have already shown that among white children, those with lighter-skin phototypes are 2-3 times more likely to have MM develop than those with darker-skin types.[3]
In addition, studies of light-skinned white children in Europe and Canada have demonstrated a clear association between a history of multiple or severe (blistering) sunburns and high nevi counts.[5,6]
Aalborg and colleagues now add to this important body of knowledge by showing that light-skinned white children who tan clearly develop a greater number of melanocytic nevi than their nontanned peers, even at an early age.
Because many MMs do not occur within existing nevi, the presence of multiple nevi in these young children likely serves as a marker for ultraviolet-induced skin damage and/or a genetic susceptibility to MM.
In this context, it seems clear that parents of light-skinned children should be educated about the benefits of photoprotecting their children to avoid tanning, starting at an early age.
Most Patients With Vaccine Allergy May Be Safely Vaccinated
From Medscape Medical News
Laurie Barclay, MD
October 20, 2009 — Most patients with vaccine allergy may be safely vaccinated, according to a practice parameter published in the October issue of the Annals of Allergy, Asthma & Immunology. However, the new guidelines also recommend that patients with suspected allergy to vaccines or vaccine components be evaluated by an allergist or immunologist vs simply avoiding future immunizations, which could leave patients at higher risk for infectious disease.
Specific summary statements in the parameter include the following:
Mild local reactions, fever, and other constitutional symptoms after vaccinations occur often and are not a contraindication to subsequent doses.
Anaphylactic reactions after vaccination are rare, with incidence of approximately 1 per million doses.
Even if the vaccine is not clearly the cause, all serious events occurring after vaccine administration should be reported to the Vaccine Adverse Event Reporting System.
Measurement of IgG antibody levels to the immunizing antigen in a vaccine suspected of causing a serious adverse reaction can determine if levels are protective and whether subsequent doses are needed.
Ideally, all suspected anaphylactic reactions to vaccines should be evaluated so that the responsible allergen may be identified.
Gelatin, egg protein, or other vaccine components are more likely than the immunizing agent itself to cause IgE-mediated reactions to vaccines.
Immediate-type allergy skin testing should be performed in patients who appear to have had an anaphylactic reaction after vaccination. This testing should help confirm that the reaction was IgE mediated and identify the responsible vaccine component.
If the intradermal skin test result is negative, it is extremely unlikely that the patient has IgE antibody to any vaccine component, and the patient can be vaccinated in the usual manner.
In a patient with a history suggesting anaphylactic reaction, however, it is prudent to vaccinate with the patient under observation and to have epinephrine and other emergency treatment available.
In patients with history and skin tests results suggesting an IgE-mediated reaction to a vaccine but who need additional doses of the suspected vaccine or other vaccines with shared ingredients, the clinician can consider administering the vaccine in graded doses while observing the patient.
There are other less common but more serious reactions to vaccines, but only a few represent absolute contraindications to future doses.
Pregnant women should not be given live vaccines.
Live vaccines should generally not be given to immunocompromised persons.
Epidemiologic studies have not supported associations between specific vaccines or vaccination in general with long-term sequelae such as atopy, autism, and multiple sclerosis.
"The 2 key points of the practice parameter are that (1) patients with suspected allergy to vaccines or vaccine components should be evaluated by an allergist/immunologist and (2) most patients with suspected allergy to vaccines can receive vaccination safely," the guidelines authors conclude.
Ann Allergy Asthma Immunol. 2009;103:S1-14.
Laurie Barclay, MD
October 20, 2009 — Most patients with vaccine allergy may be safely vaccinated, according to a practice parameter published in the October issue of the Annals of Allergy, Asthma & Immunology. However, the new guidelines also recommend that patients with suspected allergy to vaccines or vaccine components be evaluated by an allergist or immunologist vs simply avoiding future immunizations, which could leave patients at higher risk for infectious disease.
Specific summary statements in the parameter include the following:
Mild local reactions, fever, and other constitutional symptoms after vaccinations occur often and are not a contraindication to subsequent doses.
Anaphylactic reactions after vaccination are rare, with incidence of approximately 1 per million doses.
Even if the vaccine is not clearly the cause, all serious events occurring after vaccine administration should be reported to the Vaccine Adverse Event Reporting System.
Measurement of IgG antibody levels to the immunizing antigen in a vaccine suspected of causing a serious adverse reaction can determine if levels are protective and whether subsequent doses are needed.
Ideally, all suspected anaphylactic reactions to vaccines should be evaluated so that the responsible allergen may be identified.
Gelatin, egg protein, or other vaccine components are more likely than the immunizing agent itself to cause IgE-mediated reactions to vaccines.
Immediate-type allergy skin testing should be performed in patients who appear to have had an anaphylactic reaction after vaccination. This testing should help confirm that the reaction was IgE mediated and identify the responsible vaccine component.
If the intradermal skin test result is negative, it is extremely unlikely that the patient has IgE antibody to any vaccine component, and the patient can be vaccinated in the usual manner.
In a patient with a history suggesting anaphylactic reaction, however, it is prudent to vaccinate with the patient under observation and to have epinephrine and other emergency treatment available.
In patients with history and skin tests results suggesting an IgE-mediated reaction to a vaccine but who need additional doses of the suspected vaccine or other vaccines with shared ingredients, the clinician can consider administering the vaccine in graded doses while observing the patient.
There are other less common but more serious reactions to vaccines, but only a few represent absolute contraindications to future doses.
Pregnant women should not be given live vaccines.
Live vaccines should generally not be given to immunocompromised persons.
Epidemiologic studies have not supported associations between specific vaccines or vaccination in general with long-term sequelae such as atopy, autism, and multiple sclerosis.
"The 2 key points of the practice parameter are that (1) patients with suspected allergy to vaccines or vaccine components should be evaluated by an allergist/immunologist and (2) most patients with suspected allergy to vaccines can receive vaccination safely," the guidelines authors conclude.
Ann Allergy Asthma Immunol. 2009;103:S1-14.
Tuesday, October 27, 2009
Strategies for Diagnosing and Treating Dehydration in Children
From Medscape Medical News CME
Laurie Barclay , Désirée Lie,
10/16/2009
Clinical Context
Fluid and electrolyte disturbances form diarrhea and vomiting result in 1.5 million patient visits yearly in the US and 300 deaths. Several methods are available to assess hydration and the need for rehydration and hospital admission in children.
This is a review of the clinical assessment of dehydration in children with diarrhea and vomiting and recommended strategies for rehydration at home, in the office, and in the hospital.
Study Highlights
Parental report of vomiting, diarrhea, and reduced oral intake is sensitive but not specific for identifying dehydration in children.
If tear production is normal, then the chance of dehydration is low.
The most useful individual physical signs are prolonged capillary filing time, abnormal skin turgor, and abnormal respiratory pattern.
The use of scales based on combinations of physical examination findings is better than individual clinical signs.
4 factors predict dehydration: capillary refill time of more than 2 seconds, absence of tears, dry mucous membranes, and ill appearance.
The presence of 2 or more of these suggests dehydration of at least 5%. General appearance, degree of sunken eyes, dry mucous membranes, and reduced tear production are associated with length of hospital stay and the need for intravenous fluids in children.
Capillary refill time is performed at ambient room temperature on the sternum of infants and a finger or arm at the level of the heart in older children.
Skin turgor is performed by pinching the skin on the lateral abdominal wall at the umbilical level.
The ratio of serum urea nitrogen to creatinine, serum urea nitrogen alone, and urine specific gravity have poor sensitivity and specificity in children.
Serum bicarbonate levels less than 17 mEq/L may improve sensitivity of identifying hypovolemia, but levels less than 13 mEq/L are associated with poorer hydration and recovery with rehydration.
The American Academy of Pediatrics recommends ORT as the preferred treatment of fluid and electrolyte losses in children with mild to moderate dehydration with similar success as intravenous fluid replacement.
The same ORT can be used for replacement, maintenance, and rehydration.
ORT is contraindicated in abdominal ileus, altered mental status, or intestinal malabsorption.
Nasogastric rehydration with ORT is an alternative to intravenous rehydration.
As soon as rehydration is completed, children can return to an age-appropriate diet.
World Health Organization ORT contains 90 mEq/L of sodium vs 50 mEq for commercial ORT preparations, which also contain 25 g/L of dextrose and 30 mEq/L of bicarbonate, and they are recommended vs homemade solutions to reduce preparation errors.
For mild dehydration, 50 mL/kg of ORT solution should be administered with a spoon, syringe, or medicine cup by giving 1 mL/kg to the child every 5 minutes.
The Holliday-Segar method involves a rule of 1 oz per hour for infants, 2 oz per hour for toddlers, and 3 oz per hour for older children.
To replace ongoing losses, 10 mL/kg for every loose stool and 2 mL/kg for every emetic episode should be given.
For moderate dehydration, 100 mL/kg of ORT should be given for 4 hours in the office or emergency department; if treatment is successful, the child can be sent home for maintenance therapy by caregivers.
Severe dehydration should be managed with intravenous fluids until stabilization.
Treatment includes 20 mL/kg of lactated Ringer's solution for 10 to 15 minutes (repeated as needed), and up to 60 mL/kg may be needed within 1 hour.
Electrolyte measurements are important in severe and moderate dehydration.
Children with fever may require extra 1 mL/kg per degree centigrade every hour in addition to maintenance therapy.
Postoperatively and in those with infection or injury, 20% to 50% less fluid and fluid with higher sodium content may be needed.
Pharmacologic treatment is not indicated in diarrhea because of concerns of toxicity, and Lactobacillus has not been demonstrated to be useful.
A single dose of ondansetron can facilitate ORT by reducing vomiting and the need for intravenous treatment.
Clinical Implications
Physical signs predictive of dehydration include capillary refill time of more than 2 seconds, absence of tears, dry mucous membranes, and ill appearance.
ORT or nasogastric rehydration with ORT fluid is recommended for mild to moderate dehydration and intravenous rehydration for severe dehydration.
Laurie Barclay , Désirée Lie,
10/16/2009
Clinical Context
Fluid and electrolyte disturbances form diarrhea and vomiting result in 1.5 million patient visits yearly in the US and 300 deaths. Several methods are available to assess hydration and the need for rehydration and hospital admission in children.
This is a review of the clinical assessment of dehydration in children with diarrhea and vomiting and recommended strategies for rehydration at home, in the office, and in the hospital.
Study Highlights
Parental report of vomiting, diarrhea, and reduced oral intake is sensitive but not specific for identifying dehydration in children.
If tear production is normal, then the chance of dehydration is low.
The most useful individual physical signs are prolonged capillary filing time, abnormal skin turgor, and abnormal respiratory pattern.
The use of scales based on combinations of physical examination findings is better than individual clinical signs.
4 factors predict dehydration: capillary refill time of more than 2 seconds, absence of tears, dry mucous membranes, and ill appearance.
The presence of 2 or more of these suggests dehydration of at least 5%. General appearance, degree of sunken eyes, dry mucous membranes, and reduced tear production are associated with length of hospital stay and the need for intravenous fluids in children.
Capillary refill time is performed at ambient room temperature on the sternum of infants and a finger or arm at the level of the heart in older children.
Skin turgor is performed by pinching the skin on the lateral abdominal wall at the umbilical level.
The ratio of serum urea nitrogen to creatinine, serum urea nitrogen alone, and urine specific gravity have poor sensitivity and specificity in children.
Serum bicarbonate levels less than 17 mEq/L may improve sensitivity of identifying hypovolemia, but levels less than 13 mEq/L are associated with poorer hydration and recovery with rehydration.
The American Academy of Pediatrics recommends ORT as the preferred treatment of fluid and electrolyte losses in children with mild to moderate dehydration with similar success as intravenous fluid replacement.
The same ORT can be used for replacement, maintenance, and rehydration.
ORT is contraindicated in abdominal ileus, altered mental status, or intestinal malabsorption.
Nasogastric rehydration with ORT is an alternative to intravenous rehydration.
As soon as rehydration is completed, children can return to an age-appropriate diet.
World Health Organization ORT contains 90 mEq/L of sodium vs 50 mEq for commercial ORT preparations, which also contain 25 g/L of dextrose and 30 mEq/L of bicarbonate, and they are recommended vs homemade solutions to reduce preparation errors.
For mild dehydration, 50 mL/kg of ORT solution should be administered with a spoon, syringe, or medicine cup by giving 1 mL/kg to the child every 5 minutes.
The Holliday-Segar method involves a rule of 1 oz per hour for infants, 2 oz per hour for toddlers, and 3 oz per hour for older children.
To replace ongoing losses, 10 mL/kg for every loose stool and 2 mL/kg for every emetic episode should be given.
For moderate dehydration, 100 mL/kg of ORT should be given for 4 hours in the office or emergency department; if treatment is successful, the child can be sent home for maintenance therapy by caregivers.
Severe dehydration should be managed with intravenous fluids until stabilization.
Treatment includes 20 mL/kg of lactated Ringer's solution for 10 to 15 minutes (repeated as needed), and up to 60 mL/kg may be needed within 1 hour.
Electrolyte measurements are important in severe and moderate dehydration.
Children with fever may require extra 1 mL/kg per degree centigrade every hour in addition to maintenance therapy.
Postoperatively and in those with infection or injury, 20% to 50% less fluid and fluid with higher sodium content may be needed.
Pharmacologic treatment is not indicated in diarrhea because of concerns of toxicity, and Lactobacillus has not been demonstrated to be useful.
A single dose of ondansetron can facilitate ORT by reducing vomiting and the need for intravenous treatment.
Clinical Implications
Physical signs predictive of dehydration include capillary refill time of more than 2 seconds, absence of tears, dry mucous membranes, and ill appearance.
ORT or nasogastric rehydration with ORT fluid is recommended for mild to moderate dehydration and intravenous rehydration for severe dehydration.
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