Although it may be difficult to make a distinction between
retropharyngeal abscess, and retropharyngeal cellulitis attributable to
organisms such as Group A bete-haemolytic Streptococcus, Staphylococcus
Aureus, and Group B Streptococcus(1), retropharyngeal abscess should
remain high in the differential diagnosis because Fusobacterium
necrophorum(F necrophorum), the gram negative culprit pathogen,although
initially givin...
Although it may be difficult to make a distinction between
retropharyngeal abscess, and retropharyngeal cellulitis attributable to
organisms such as Group A bete-haemolytic Streptococcus, Staphylococcus
Aureus, and Group B Streptococcus(1), retropharyngeal abscess should
remain high in the differential diagnosis because Fusobacterium
necrophorum(F necrophorum), the gram negative culprit pathogen,although
initially giving rise to pharyngitis(2)or to tonsillitis(3), may
ultimately mandate an antibiotic regime different from the one typically
used for treatment of gram positive infections(4). Among 14 cases of
bacteriologically confirmed F necrophorum infection diagnosed in a
children's hospital, the organism was isolated from peritonsillar abscess
fluid in eight, from blood cultures in five, and from bronchial-alveolar
lavage fluid in one. Lemierre's syndrome(LS) was a complication in four of
these bacteriologically confirmed cases. Of note, among two of the four
bacteriologically validated cases of LS there was serological evidence
suggestive of co-infection with two of the organisms more commonly
associated with tonsillitis. In one instance, the serological evidence
amounted to elevation in Anti Streptolysin O Titre, and, in the other, it
amounted to documentation of a positive Immunoglobulin M titre for Epstein
-Barr Virus(2), the latter generally beleived to be "virtually diagnostic
of primary EBV infection"(5). Accordingly, to paraphrase one commentator,
these cases "draw attention to an alternative pathogen for
tonsillitis"(4), thereby justifying a high index of suspicion for F
necrophorum. In the event that the oragnism cannot be isolated by culture
from appropriate specimens molecular methods, including broad-range 16S
rDNA PCR should be used. The latter startegy has the advantage that it
also encompasses other bacterial infections, such as Group A Streptococci,
Staphylococcus Aureus, and Streptococcus pneumoniae, presenting with
similar clinical features. Furthermore, because the test dtects molecular
material from bacteria, previous antibiotic treatment does not interfere
with the diagnosis(6).
References
(1)Zacharkiwa A., Williams H
A pain in the neck
Arch Dis Child Ed Pract 2013;98:71-72
(2)Ramirez S., Hild TG., Rudolph CN et al
Increased diagnosis of Lemierre Syndrome and other Fusobacterium
necrophorum infections in a children's hospital
Pediatrics 2003;112:e380-e385
(3)Klug TE., Henriksen J-J., Fuursted K., Ovensen T
Significant pathogens in peritonsillar abscess
Eur J Clin Microbiol Infect Dis 2011;30:619-627
(4)Fourage M., Bourguignat C., Fermond B., Delobel P
A recurrent tonsillitis
Lancet 2013;381:266
(5)Luzuriaga K., Sullivan JL
Infectious mononucleosis
N Engl J Med 2010;362:1993-2000
(6)Patel M
16S rDNA PCR in diagnosis of Lemierre's syndrome
Lancet Infectious Diseases 2013;13:197
Carter and colleagues have done a superb job in summarising the
theory and practice of tools used in assessing children for autism.
Unfortunately their paper is marred by a mathematical error which, if left
unchallenged, could undermine trust in the use of one such tool, the ADOS.
According to the paper, the positive predictive value (ppv, i.e. the
proportion of those who test positive who actually have the cond...
Carter and colleagues have done a superb job in summarising the
theory and practice of tools used in assessing children for autism.
Unfortunately their paper is marred by a mathematical error which, if left
unchallenged, could undermine trust in the use of one such tool, the ADOS.
According to the paper, the positive predictive value (ppv, i.e. the
proportion of those who test positive who actually have the condition) of
the ADOS is 80.4% in a neurodevelopmental clinic population, whilst the
negative predictive value (npv, proportion of those who test negative who
do not have the condition) in the same population is only 11.9%. If this
were true it would mean that the proportion of those in the test negative
group who have the condition would actually be higher than in the test
positive group- 88.1% against 80.4%. Fortunately it is not true.
Using the population prevalence of 53% quoted, and the figures of 91%
sensitivity and 75% specificity the true figure for ppv is as given, but
the npv is actually 87.5%. Carter et al's conclusion, therefore, that
tests should be interpreted in the light of history and information from
other sources stands, but the ADOS is not as hopeless as their paper might
have suggested.
As part of the team that undertook review of the paper prior to
publication I would like to thank Alan for picking up this
misinterpretation and to apologise to our readers for the mistake.
It's entirely correct that a negative ADOS will be right - the
patient will not have autism - about 88% of the time.
The table 3 is misleadingly titled "prob that the test rules out
autism" and should be "post test...
As part of the team that undertook review of the paper prior to
publication I would like to thank Alan for picking up this
misinterpretation and to apologise to our readers for the mistake.
It's entirely correct that a negative ADOS will be right - the
patient will not have autism - about 88% of the time.
The table 3 is misleadingly titled "prob that the test rules out
autism" and should be "post test probability of autism with a negative
test" and this mistake is repeated in the text.
I think there's something in the way we describe the 'output' of a
diagnostic test.
Sometimes the value of a negative test is given as NPV ie the % with
a negative test who are negative for the condition.
Sometimes it's given as the predictive value of a negative test ie
the % of those with a negative test that DO HAVE the disorder
Personally, I prefer this latter way of presenting the information as
it highlight the negative test 'failures' who you may have 'dismissed'.
So - while it's true that a negative ADOS is right ~88% of the time,
that's the same as saying about 12% of the time a patient with negative
ADOS actually does have an autistic spectrum disorder.
The reservations exepressed about the interpretation of interferon
gamma release assays(IGRAs)(1)are underpinned by the following
observations:-
IGRAs do not reliably identify subjects with active tuberculosis(even in
the context of culture positive disease)(2), as shown by a study where 45
subjects received a diagnosis of active tuberculosis characterised, in 37
of those subjects, by positive cultures for mycobacterium...
The reservations exepressed about the interpretation of interferon
gamma release assays(IGRAs)(1)are underpinned by the following
observations:-
IGRAs do not reliably identify subjects with active tuberculosis(even in
the context of culture positive disease)(2), as shown by a study where 45
subjects received a diagnosis of active tuberculosis characterised, in 37
of those subjects, by positive cultures for mycobacterium
tuberculosis(MTB). Nevertheless, in 17 of the 45 patients with a final
diagnosis of active tuberculosis the IGRA test was negative(2). This means
that, in that study,the spectrum of 17 negative IGRA tests included, at a
bare minimum, at least eight patients with culture positive tuberculosis.
The suboptimal sensitivity of IGRAs is compounded by apparently
spontaneous reversion from positive to negative test status(3)(4), and
also by apparently spontaneous by conversion from negative to positive
test status(3)(4). This state of affairs has implications for recognition
and management of latent tuberculosis, not only in the context of low
disease prevalence(3), but also in the context of high disease
prevalence(4). In the former context, an American study utilised IGRAs to
screen 3,234 individuals considered to be at low risk of mycobacterium
tuberculosis infection, including low risk of infection in the remote
past. Of these, 2,819 tested unequivocally negative, 218 tested
unequivocally positive, and 177 yielded indeterminate tests per
manufaturer's criteria. On retesting 13(9%) of initially negative tests
converted to positive, and 15(7%) of initially positive tests reverted to
negative test status using the manufacturer's cut-off value(3). In the
context of high disease prevalence a review was published which included
evaluation of in-subject variability of IGRAs in India and in South
Africa. In the Indian context, over a 2 weeks period, 2 of 14 health care
workers experienced reversion from positive to negative test status. In
the South African study, over a 3 week period, 7 of 26 helth care workers
experienced either a conversion or a reversion. In both the Indian and the
South African studies subjects who experienced either reversion or
conversion had initial values close to the cut-off point(4).
These observations(2)(3)(4) should serve as fundamental caveats to the use
of IGRAs in clinical practice.
References
(1) Pollock L., Roy RB., Kampmann B
How to use: interferon gamma release assays for tuberculosis
Education and Practice 2013;98:99-105
(2)Dewan PK., Grinsdale J., Kawamura M
Low sensitivity of a whole blood interferon gamma release assay for
detection of active tuberculosis
Clinical Infectious Diseases 2007;44:69-73
(3) Metcalfe JZ., Cattamanchi A., McCulloch CE et al
Test variability of the QuabtiFERON-TB-Gold in-Tube assay in clinical
practice
Am J Respir Crit Care Med 2013;187:206-2011
(4) van Zyl Smit RN., Zwerling A., Dheda K., Pai M
Within-subject variability of interferon-gamma assay results for
tuberculosis and boosting effect of tuberculin skin testing: A systematic
review
PLoS ONE 2009;4:e8517
The Fifteen-minute consultation on the infant with a large head just
published on line (1) has one major weakness: no mention of which chart
the child's head is compared to. Comparison with representative Belgian,
Norwegian (2) and British data (3) has shown that European infants' heads
appear large compared to the WHO standards. We have undertaken further
analyses of the data from the Southampton Women's Survey used fo...
The Fifteen-minute consultation on the infant with a large head just
published on line (1) has one major weakness: no mention of which chart
the child's head is compared to. Comparison with representative Belgian,
Norwegian (2) and British data (3) has shown that European infants' heads
appear large compared to the WHO standards. We have undertaken further
analyses of the data from the Southampton Women's Survey used for our
previous paper (3) and these suggest that, out of 1731 healthy infants
aged 6 months, 3.3% have a head circumference (HC) above the WHO 99.6th
centile and half of these (1.8% of all infants) will also have crossed 2
or more centile spaces upwards since birth. Reassuringly, between 6 and 12
months there was much less centile crossing and only 5 infants (0.3% of
all infants) move further upwards by more than the equivalent of one
centile space (0.67SD). It is probably these latter children who should
be investigated further.
If compared to the previous UK 1990 growth chart only around 0.5% of
children will have a head circumference above the 99.6th, but it should be
born in mind that compared to the UK 1990 UK more infants' heads appear
small. After the age of 6 months between 5-8% of children have heads
below the UK1990 2nd centile (3) and our further analyses of the latter
data3 suggest that by 6 months of age 17% of healthy infants will have
crossed 2 or more centile spaces downwards compared to the UK 1990
reference.
So the growth chart you choose makes a huge difference: make sure you
know which one is being referred to!
Reference List
(1) Seal A. Fifteen-minute consultation on the infant with a large
head. Arch Dis Child Educ Pract Ed 2013.
(2) Juliusson PB, Roelants M, Hoppenbrouwers K, Hauspie R, Bjerknes R.
Growth of Belgian and Norwegian children compared to the WHO growth
standards: prevalence below -2 and above +2 SD and the effect of
breastfeeding. Arch Dis Child 2011; 96(10):916-921.
(3) Wright CM, Inskip HM, Godfrey K, Williams AF, Ong KK. Monitoring head
size and growth using the new UK-WHO growth standard. Arch Dis Child 2011;
96(4):386-388.
Conflict of Interest:
I am academic lead for the RCPCH growth chart group that published the new UK-wHO growth charts
I read with interest "The Fifteen-minute consultation on the infant
with a large head" published recently by Arnab Seal.
Clinicians should also be aware of 'Benign Enlargement of Subarachnoid
Space (BESS)'. It is described under various names in literature including
benign extra-axial collections of infancy, external hydrocephalus,
subdural effusions, etc (1).
It presents in infancy with rapid enlarged of head circumferen...
I read with interest "The Fifteen-minute consultation on the infant
with a large head" published recently by Arnab Seal.
Clinicians should also be aware of 'Benign Enlargement of Subarachnoid
Space (BESS)'. It is described under various names in literature including
benign extra-axial collections of infancy, external hydrocephalus,
subdural effusions, etc (1).
It presents in infancy with rapid enlarged of head circumference on the
background of normal development.
It should be differentiated from isolated or familial macrocephaly as the
head circumference is normal at birth followed by rapid growth in infancy
crossing more than 2 centiles. Hence although it would fall in category E
(figure 2) neuroimaging (Computed tomography (CT)/Magnetic resonance
imaging (MRI) head) would be required to rule out any intracranial
pathology and establish the diagnosis. In the majority of cases there is a
positive family history of macrocephaly, thus can be misdiagnosed as
familial macrocephaly if neuroimaging is not undertaken.
The anterior fontanelle is enlarged along with enlargement of fronto-
parietal subarachnoid space. There is no associated brain atrophy or signs
of raised intracranial pressure.
As the name indicates it is completely benign condition and no surgical
intervention is required. This condition is self-limiting with spontaneous
resolution usually by 2 years of age. Although the macrocephaly may
persist it plateaus by 2 years of age and associated with resolution of
subarachnoid space as the child grow older (1).
It is important to monitor the head growth and developmental progress. If
there is any deviation from normal in neuro-development or there is
persistence of rapid head growth beyond 2 years of age further evaluation
is required to exclude other intracranial pathologies (2).
In summary, clinicians should consider BESS in any infant presenting with
rapid head growth and normal development. This is a benign self-limiting
condition and no surgical intervention is required.
I read with interest the "Fifteen minute consultation: headache in
children under 5 years of age" recently published online.
It would also be worth remembering and will be reassuring to all of us to
know that although some characteristics of early-onset headache can be
different from that of late-onset headaches for e.g. shorter duration, the
overall impact of the headache on the school performance and learning and
clini...
I read with interest the "Fifteen minute consultation: headache in
children under 5 years of age" recently published online.
It would also be worth remembering and will be reassuring to all of us to
know that although some characteristics of early-onset headache can be
different from that of late-onset headaches for e.g. shorter duration, the
overall impact of the headache on the school performance and learning and
clinical severity do not significantly differ from the later.
In other words, early-onset of headaches does not necessarily imply
poorer long term headache disability or harmful aetiology. (1)
Reference:
1. Ravid S, Gordon S, Schiff Aet. al. Headache in Children: Young Age at
Onset Does Not Imply a Harmful Etiology or Predict a Harsh Headache
Disability. Journal of Child Neurology2013: 28(7) 857-862
We welcome Santhakumaran's article (1) describing some of the
problems and misunderstandings that can arise when adjusting for case-mix
differences between hospitals. In our recent paper (2) we quantified the
bias that is likely to arise when comparing standardised mortality ratios
(SMRs) between one neonatal unit and another. In our paper it was shown
that, using actual observed differences in case-mix, even if two neo...
We welcome Santhakumaran's article (1) describing some of the
problems and misunderstandings that can arise when adjusting for case-mix
differences between hospitals. In our recent paper (2) we quantified the
bias that is likely to arise when comparing standardised mortality ratios
(SMRs) between one neonatal unit and another. In our paper it was shown
that, using actual observed differences in case-mix, even if two neonatal
units were performing identically for each patient group the ratio of
their SMRs could range from 0.79 to 1.68.
However, this is not to say that the SMR has no role when reporting
of clinical outcomes. First, when case-mix differences are small the
likely bias that occurs when comparing two SMRs is also likely to be
small. Second, the value of the SMR can indicate where intervention (e.g.
training, guidelines) may be the most beneficial. For example, with
Santhakumaran's two hypothetical neonatal units (Table 1 (1)) it seems
entirely reasonable for the hypothetical manager to conclude that
prioritizing intervention in unit A (the unit with the highest SMR) would
result in improved outcomes for more patients than would the same
intervention in unit B, since there are more deaths in unit A than in unit
B.
1 Santhakumaran S. How to adjust for case-mix when comparing outcomes
across healthcare providers Arch Dis Child Educ Pract Ed Published Online
First: 30 September 2013 doi:10.1136/archdischild-2013-303940
2 Evans TA, Seaton SE, Manktelow BN. Quantifying the potential bias
when directly comparing standardised mortality ratios for in-unit neonatal
mortality. PLoS ONE 8(4):e61237
Dear Editor,
We read with interest the article by Peter A Lio et. al. (1). With regards
to question no.2, the authors have rightly pointed out that
Neurofibromatosis Type 1 (NF1) is the most likely diagnosis.
Once the diagnosis of NF1 is confirmed, an affected individual should
have a thorough initial assessment with particular attention to features
of NF1, a physical examination with particular attention to the s...
Dear Editor,
We read with interest the article by Peter A Lio et. al. (1). With regards
to question no.2, the authors have rightly pointed out that
Neurofibromatosis Type 1 (NF1) is the most likely diagnosis.
Once the diagnosis of NF1 is confirmed, an affected individual should
have a thorough initial assessment with particular attention to features
of NF1, a physical examination with particular attention to the skin,
skeleton, cardiovascular system & neurological systems, ophthalmologic
evaluation including slit lamp examination and developmental assessment in
children.
Ongoing surveillance should include annual physical examination
comprising regular blood pressure monitoring, annual head circumference
monitoring (rapid increase might indicate tumour or hydrocephalus, annual
ophthalmologic examination (including fundoscopy and visual fields) until
age 7, regular developmental and growth assessment.Further investigations
as indicated.
However, we are aware that presently in this child's case only one
criteria for diagnosis is met. As the diagnosis of NF1 has major
implications for the child and the family, we would be interested in
finding out whether one should confirm the diagnosis at this stage with
genetic test and start the surveillance process as per the guidelines (2)
or should one wait for the second major criteria to appear?
Reference:
1. Peter A Lio, Kachiu C Lee. Brown birthmarks. Arch Dis Child Educ Pract
Ed 2013;98:171-172
2. Ferner RE, Huson SM, Thomas N, et al. Guidelines for the diagnosis and
management of individuals with neurofibromatosis 1. J Med Genet 2007;44:81
-88
Sascha Meyer (MD), Isabel Oster (MD), Sylvia Peterlini (MD), Ludwig
Gortner (MD, Professor), Georg Kutschke (MD)
Dear Sir and Madam,
We read with interest the 15 minute consultation on recurrent oral
ulceration in a child by Le Doare et al. (1). In their report, the authors
provide a wide range of differential diagnoses that may lead recurrent
oral ulcerations (1).
Sascha Meyer (MD), Isabel Oster (MD), Sylvia Peterlini (MD), Ludwig
Gortner (MD, Professor), Georg Kutschke (MD)
Dear Sir and Madam,
We read with interest the 15 minute consultation on recurrent oral
ulceration in a child by Le Doare et al. (1). In their report, the authors
provide a wide range of differential diagnoses that may lead recurrent
oral ulcerations (1).
In our opinion, it is important to take into consideration other
causes for oral ulcers in children - most importantly recurrent seizures
(2, 3). This is of great importance because in addition to local treatment
and use of a bite guard, administration of anti-epileptic drugs is of
utmost importance. This medical problem is illustrated in Fig. 1 and Fig.
2.
With kind regards
Sascha Meyer, Isabel Oster, Sylvia Peterlini, Ludwig Gortner, Georg
Kutschke
University Children`s Hospital of Saarlnd
66421 Homburg
Germany
References:
1) Le Doare K, Hullah E, Challacombe S, Menson E. Fifteen-minute
consultation: a structured approach to the management of recurrent oral
ulceration in a child. Arch Dis Child Educ Pract Ed. 2013 Sep 19. doi:
10.1136/archdischild-2013-304471. [Epub ahead of print].
2) Cerqueira DF, Vieira AS, Maia LC, Sweet E. Severe tongue injury in an
adolescent with epilepsy: a case report. Spec Care Dentist. 2007 Jul-
Aug;27(4):154-7.
3) Sanders BJ, Weddell JA, Dodge NN. Managing patients who have seizure
disorders: dental and medical issues. J Am Dent Assoc. 1995
Dec;126(12):1641-7.
Figure 1: Multiple oral and tongue ulcers in a 2-year-old-girl
Figure 2: Sleep EEG recording demonstrating generalized seizure
activity accompanied by a short episode of myoclonus, increased oral
muscular tone, and bleeding from the oral cavity
Although it may be difficult to make a distinction between retropharyngeal abscess, and retropharyngeal cellulitis attributable to organisms such as Group A bete-haemolytic Streptococcus, Staphylococcus Aureus, and Group B Streptococcus(1), retropharyngeal abscess should remain high in the differential diagnosis because Fusobacterium necrophorum(F necrophorum), the gram negative culprit pathogen,although initially givin...
Carter and colleagues have done a superb job in summarising the theory and practice of tools used in assessing children for autism. Unfortunately their paper is marred by a mathematical error which, if left unchallenged, could undermine trust in the use of one such tool, the ADOS.
According to the paper, the positive predictive value (ppv, i.e. the proportion of those who test positive who actually have the cond...
As part of the team that undertook review of the paper prior to publication I would like to thank Alan for picking up this misinterpretation and to apologise to our readers for the mistake.
It's entirely correct that a negative ADOS will be right - the patient will not have autism - about 88% of the time.
The table 3 is misleadingly titled "prob that the test rules out autism" and should be "post test...
The reservations exepressed about the interpretation of interferon gamma release assays(IGRAs)(1)are underpinned by the following observations:- IGRAs do not reliably identify subjects with active tuberculosis(even in the context of culture positive disease)(2), as shown by a study where 45 subjects received a diagnosis of active tuberculosis characterised, in 37 of those subjects, by positive cultures for mycobacterium...
The Fifteen-minute consultation on the infant with a large head just published on line (1) has one major weakness: no mention of which chart the child's head is compared to. Comparison with representative Belgian, Norwegian (2) and British data (3) has shown that European infants' heads appear large compared to the WHO standards. We have undertaken further analyses of the data from the Southampton Women's Survey used fo...
I read with interest "The Fifteen-minute consultation on the infant with a large head" published recently by Arnab Seal. Clinicians should also be aware of 'Benign Enlargement of Subarachnoid Space (BESS)'. It is described under various names in literature including benign extra-axial collections of infancy, external hydrocephalus, subdural effusions, etc (1). It presents in infancy with rapid enlarged of head circumferen...
I read with interest the "Fifteen minute consultation: headache in children under 5 years of age" recently published online. It would also be worth remembering and will be reassuring to all of us to know that although some characteristics of early-onset headache can be different from that of late-onset headaches for e.g. shorter duration, the overall impact of the headache on the school performance and learning and clini...
We welcome Santhakumaran's article (1) describing some of the problems and misunderstandings that can arise when adjusting for case-mix differences between hospitals. In our recent paper (2) we quantified the bias that is likely to arise when comparing standardised mortality ratios (SMRs) between one neonatal unit and another. In our paper it was shown that, using actual observed differences in case-mix, even if two neo...
Dear Editor, We read with interest the article by Peter A Lio et. al. (1). With regards to question no.2, the authors have rightly pointed out that Neurofibromatosis Type 1 (NF1) is the most likely diagnosis.
Once the diagnosis of NF1 is confirmed, an affected individual should have a thorough initial assessment with particular attention to features of NF1, a physical examination with particular attention to the s...
Sascha Meyer (MD), Isabel Oster (MD), Sylvia Peterlini (MD), Ludwig Gortner (MD, Professor), Georg Kutschke (MD)
Dear Sir and Madam,
We read with interest the 15 minute consultation on recurrent oral ulceration in a child by Le Doare et al. (1). In their report, the authors provide a wide range of differential diagnoses that may lead recurrent oral ulcerations (1).
In our opinion, it is import...
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