Symptoms
and Signs
in Infants
Younger
Than
6
Months
of Age Correlated
With the Severity
of
Their
Illness
C. J. Morley,
MD, FRCP,
DCH;
A. J. Thornton,
BA, SRN;
T. J. Cole,
PhD*;
M. A. Fowler;
and
P. H. Hewson,
MD, FRACP*
From the Department of Paediatrics, University of Cambridge, England, * MAC Dunn
Nutrition Laboratory, Cambridge, and
f
Department of General Paediatrics, Royal Children’s Hospital, Melbourne, AustraliaABSTRACT. Symptoms and signs were recorded for 1007 infants younger than 6 months of age seen at home (298) or hospital (709) and correlated with four grades of illness severity. Most symptoms, present in the preceding 3 days, were associated with all grades of illness. Only four symp-toms were not reported in well infants: a fluid intake less than a third of normal, convulsions, frank blood in the stools, and bile-stained vomiting. By comparison, many signs were seen only in ill infants. Those associated only with moderate or serous illness were marked retraction of the lower ribs, high-pitched or moaning cry, expiratory grunt, loss of alertness, central cyanosis, and severe hy-potonia. Although these will not identify all seriously ill infants, parents and professionals should be taught to recognize these important symptoms and signs of serious illness. Pediatrics 1991;88:1119-1124; infant, illness,
symptoms, signs.
The first 6 months of life is the period when
infants are at most risk of serious illness or death. Deciding whether an infant is seriously ill is a skill
developed from experience by pediatricians and
children’s nurses. Mothers recognize when their
infants are unwell but sometimes find it difficult to
assess the severity of the infant’s illness.1 Family
doctors and junior pediatric staff also may find it
difficult to judge when symptoms and signs indicate
a potentially serious illness.2 Unfortunately,
text-books contain little information about which
symp-toms and signs are important and which are too
common to be useful. Individual symptoms and
Received for publication Feb 20, 1990; accepted Oct 10, 1990. Reprint requests to (C.J.M.) Dept of Paediatrics, Addenbrooke’s Hospital, Cambridge, CB2 2QQ, England.
PEDIATRICS (ISSN 0031 4005). Copyright © 1991 by the American Academy of Pediatrics.
signs which may be useful markers of serious illness
in infants at hospital may be so common in the
community in well or mildly ill infants that they
have a low predictive value for serious illness.35 A
British Medical Journal editorial6 on preventing
infant deaths noted that “the incidence of sinister
symptoms in the community needs to be assessed,
and objective methods of assessing serious illness
in infants must be taught” and a recent House of
Commons Social Services Committee report7 called
for improvement in the training of family doctors
in the recognition of ill infants and pointed out a
need for more information about the important
symptoms and signs of illness in young infants.
This paper describes the prevalence of individual
symptoms and signs in infants who were well,
mildly ill, moderately ill, or seriously ill.
METHODS
To determine with reasonable accuracy whether
individual symptoms and signs are associated with
serious illness each one, even the rarest, needs to
be recorded at least five times.8 As serious illness
occurs in fewer than 1% of infants at home on any
day and the rarest signs may occur in fewer than
1% of seriously ill infants, a study would need to
enroll thousands of infants to assess the prevalence
of all symptoms and signs in seriously ill infants in
the community. This would be impossible to
achieve. However, we calculated that the study was
possible if 600 infants were enrolled when they
presented to the hospital, where the incidence of
serious illness is much higher than at home. This
number would ensure that a rare sign of serious
would be detected with 90% power at the 5% level.
Three hundred infants enrolled at home would be
sufficient to quantify the prevalence of all but the
rarest symptoms and signs in the community.
A total of 1007 infants younger than 6 months of
age were assessed in two centers during 1 year, 298
at home and 709 when they presented to the
hos-pita!. Each infant was seen by one of two assessors
(P.H.H. in Melbourne or A.J.T. in Cambridge) who
had practiced the assessment together and worked
from a detailed protocol.3’5’#{176}
The 298 full-term infants whose mothers spoke
English and lived within 5 miles of the hospital,
were chosen at random from the birth register (2
per day, on 3 days per week, for 1 year) and seen at
home in Cambridge. One infant was in the hospital
with pneumonia at the time of the assessment and
1 died suddenly at home before being assessed.3
They were all assessed on a predetermined date to
ensure that they were seen evenly across the first 6
months of life and the four seasons.
At the hospital, 709 infants younger than 6
months of age were enrolled prospectively when
they were brought from home for assessment of an
illness ofless than 15 days’ duration. Up to 6 infants
per day were assessed during working hours, on 3
days per week, for 1 year. There were 682 in
Mel-bourne and 27 in Cambridge; 180 were admitted
and 529 sent home; 2 died. The infants seen in the
hospital had a broad spectrum of diagnoses.5’9
The mother was asked whether the infant had
exhibited any of 28 symptoms in the previous 24
hours. The symptoms were defined to prevent
misunderstanding’5 (see Appendix). The duration
and severity of each symptom were recorded. Some
were quantified (eg, number of stools or vomits).
Each infant was then examined according to the
protocol.
As there is no gold standard for grading the
severity of each infant’s illness, they were
catego-rized by the assessors (P.H.H. and A.J.T.) into four
groups: well; mildly ill (not needing medical
treat-ment at the moment); moderately ill (needs to be
assessed, treated if necessary, and reviewed); or
seriously ill (needs admitting to the hospital). The
two assessors had developed and practiced the
as-sessment to minimize interobserver error. For
com-parison, each infant’s illness was also graded, where possible, using two other criteria: positive investi-gation results; and a consensus of a retrospective
review of the hospital notes by three experienced
pediatricians who classified the illness as (1) needed hospital treatment, (2) needed hospital observation,
or (3) could be cared for at home.5’9 After comparing
the accuracy of each of these criteria to grade the
severity of illness, the assessor’s impression of the
illness was chosen because it was done for all
in-fants at the time they were seen and there was a
high level of concordance between the assessor’s
impression and the independent pediatricians’
re-view (K = 0.62, P < .001).b0 There was a similar
level of concordance with positive investigation
re-sults.
RESULTS
Table 1 shows the grading of illness for all the
infants in the cohort and the subgroups of infants
at home and in the hospital.
The symptoms and signs that are likely to be
most useful for accurately indicating which infants
are ill are those that are not found in well infants.
In this study, with 290 well infants, a zero
preva-lence means that the symptom or sign occurred in
fewer than 1:290 (95% confidence interval 0% to
1.2%).
Symptoms
Table 2 shows the prevalence of each symptom
for each grade of illness ordered with reducing
prevalance in well infants. Those symptoms that
did not occur in well infants were as follows: a fluid
intake in the last 24 hours of less than a third of
normal, convulsions, frank blood in the stools, and
bile-stained vomit. These are obviously important
and need medical attention. All other symptoms
were reported for infants with all grades of illness.
The symptoms that were rare in well infants
(oc-curring in fewer than 1%; see Table 2) were as
follows: breathing difficulty, vomiting at least half
of each feed after the last three feeds, projectile
vomiting, passing small amounts of urine, cyanotic
or apneic episodes, jaundice, and drowsiness most
of the time.
Signs
Table 3 shows the prevalence of each of the signs
for each grade of illness ordered with reducing
prevalence in well infants. Many signs were not
seen in well infants (see lower half of Table 3) and
are therefore useful indicators of illness. The signs
that are more sensitive because they were seen only
in moderately or seriously ill infants were as
fol-lows: obvious retraction of the lower ribs, a
high-pitched or moaning cry, and an audible expiratory
grunt. Signs seen only in seriously ill infants were
as follows: no eye contact with the examiner,
cen-tral cyanosis, complete lack of awareness of the
TABLE 1. Proportion of Infants With Different Grades of Illness in Each Location*
Location Total Well Mildly
Ill
Moderately Ill
Seriously Ill
Home 299t 239 (80) 51 (17) 8 (2.7) 11 (0.3)
Hospital 709 51 (7) 254 (36) 239 (34) 165 (23)
Both sites 1008t 290 (29) 305 (30) 247 (24.5) 166t (16.5)
* Values are given as number (percent).
t One infant who was on the schedule to be seen at home had been admitted to hospital with severe pneumonia at the time of the assessment. This infant has not been included in the analyses but is included here to indicate that serious illness at home occurs in fewer than 0.3% of infants.
TABLE 2. Proportion of Infants in Each Illness Grade With Each Symptom*
Symptom Well Mildly Ill Moderately Ill Seriously Ill
(n = 290) (n = 305) (n = 247) (n = 165)
Increased irritability 8 43 61 78
Cough (>5 episodes/d) 6 28 39 34
Runny nose 6 21 30 26
Not himself/herself 5 43 59 79
Not feeding normally 5 30 51 71
Noisy breathing 5 29 36 43
Feels hot 5 22 47 53
An abnormal cry 4 27 47 69
Vomiting (not possetting) 3 21 32 41
Diarrhea 3 15 25 27
Cold hands and feet 3 13 27 39
Pallor 3 13 29 56
Sweating 2 16 19 33
Fluids intake, approx half normal 1 15 29 36
Drowsiness-occasionally 1 6 25 53
Decreased activity 1 6 15 46
Breathing difficulty <1 15 28 34
Vomiting more than half the feed <1 7 12 10
after the last 3 feeds
Projectile vomiting <1 5 9 10
Lessurine <1 5 17 34
Cyanotic episodes <1 3 5 12
Apneic episodes <1 3 5 4
Jaundice <1 1 0 <1
Drowsy-most of the time <1 <1 7 35
Fluids less than #{189}normal intake 0 1 3 19
Convulsions 0 1 <1 4
Blood in stools (not streaks) 0 <1 <1 5
Bile-stained vomiting 0 0 <1 3
* For the definition of each symptom see Appendix. Values are given in percentages.
DISCUSSION
There is no absolute standard by which to grade
the severity of an infant’s illness; therefore, the
relation of the symptoms and signs to different
illness grades has to be subjective. As P.H.H., an
experienced pediatrician, assessed more than 95%
of the ill infants, the association of the symptoms and signs with each grade of illness are a reflection of his experience and clinical judgment.
The study was conducted in two locations, where
the prevalence of disease was different. This might
influence the combined results. However, when the
two centers were compared, the signs and
symp-toms of specific diseases and different grades of
illness were not significantly different in the two
locations,” ie, an infant with bronchiolitis or
gas-troenteritis in Melbourne had similar signs and
symptoms to one in Cambridge.
This paper has related the symptoms and signs
to grades of illness severity rather than diagnoses
for three reasons: (1) When infants become ill, their
symptoms and signs are often nonspecific and it is
not easy to make a firm diagnosis. (2) The severity
of illness in specific diagnostic categories (eg, gas-troenteritis or viral respiratory infections) can vary
so much that the diagnosis alone does not help
decide how ill an infant is. (3) Parents and doctors
mdi-Sign Well
(n = 290)
76 72
32 24
Mildly Ill
(n= 305)
69 69 42 33
Moderately Ill
(n= 247)
70
81
54 50
Seriously Ill
(n= 165)
62
76
82 62 Respiratory rate >50/mm
Pulse rate >140/mm Not smiling at examiner Intermittent cry during
exami-nation
Mild retraction of lower ribs 7 20 44 43
Rash (moderate or severe) 3 14 17 12
Big toe squeeze-color return 3 12 23 31
takes >3 5
Mild hypotonia 3 11 22 36
Persistent cry during examina- 3 2 5 10
tion
Soft tissue mass (>2 cm diame- 3 2 2 6
ter)
Nasal discharge 2 9 8 5
Peripheral cyanosis 2 2 6 15
Hyperinflation of the chest 2 1 7 19
Stridor 2 1 3 3
Pale arms and legs 1 8 16 29
Wheeze <1 4 14 17
Calves feel cold <1 0 3 11
Bleeding into skin (any cause) <1 0 2 2
Inflamed tympanic membranes 0 6 15 11
Pallor of whole body 0 5 9 36
Partially extended posture 0 3 3 25
Distended and tense abdomen 0 2 2 6
Transient loss of eye contact 0 1 2 31
with examiner
Transient loss of awareness of 0 1 2 33
surroundings
Rectal temperature >100.8#{176}Ft 0 1 13 29
Crepitations (on auscultation) 0 <1 6 13
Cry-weak or whimpering 0 <1 5 23
Reduced hydration 0 <1 2 12
Obvious sweating 0 <1 2 3
Inguinal hernia 0 <1 1 5
Palpable mass in abdomen 0 <1 1 6
Tender abdomen on palpation 0 <1 <1 17
Obvious retraction of lower ribs 0 0 3 6
Cry-high pitched or moaning 0 0 <1 67
Expiratory grunt-audible 0 0 <1 7
No eye fixation with examiner 0 0 0 5
Central cyanosis 0 0 0 5
No awareness of surroundings 0 0 0 3
Completely extended posture 0 0 0 2
* Values are given in percentages.
t >38.2#{176}C.
TABLE 3. Proportion of Infants in Each Illness Category With Each Sign*
cate a serious illness which needs further attention
even though the diagnosis may not be obvious.
Positive predictive values of individual symptoms
or signs indicate the chance of an infant’s being ill
when those symptoms or signs are present. These
have not been calculated for this paper because the
predictive value of any symptom or sign’s being
associated with serious illness depends on the
pop-ulation and its spectrum of illness. In this paper we
have presented data on the prevalence of each
symptom and sign in different grades of illness
severity. From these data readers could calculate
the predictive value for each symptom or sign for
each illness grade for any population depending on
the prevalence of each grade of illness in that
population. We found that serious illness occurred
in fewer than 1% of infants at home, whereas it
was present in 23% of infants taken to the hospital.
Symptoms are often referred to as if they are
present or absent.2 These data show the importance
of quantifying symptoms. Examples are vomiting
and fluid intake in Table 2. Vomiting and a reduced
fluid intake are common in infants with every grade
of illness; however, vomiting more than half the
feeds after the last three feeds and projectile
with a similar prevalence in all grades of illness. A
fluid intake reduced to less than a third of normal
is uncommon in all but seriously ill infants.
Many signs were so common in well or mildly ill
infants that they are not useful for assessing the
severity of an infant’s illness. For example,
“mu-cousy breathing” occurred in 28% of well infants
and 31% of mildly ill infants, and respiratory rate,
the subject of a separate paper,’2 can be seen (Table 3) to be a poor predictor of illness severity in infants of this age.
More of the signs than symptoms were present
only in ill infants. Signs are therefore much more
useful than a mother’s report of symptoms for
assessing the severity of an infant’s illness. An
infant’s illness cannot be assessed accurately from
the symptoms alone, and the infant must be
un-dressed and fully examined for accurate
assess-ment.
Stanton et al’3 suggested that “babies with ‘major
symptoms’ need a medical opinion the same day
and close supervision, but not necessarily treatment
in hospital.” The symptoms included were
wheez-ing, noisy or altered breathing, cough, diarrhea or
vomiting, unusual drowsiness, irritability or
exces-sive crying, altered character to the cry, not feeding
normally or having feeding difficulty, and fever or
excessive sweating. Signs were not included because
this was a study of postneonatal deaths. These
symptoms, which were derived from experience by
Stanton et a!, can now be examined in the light of
the objective data from this paper. Many of Stanton
and coworkers’ symptoms are reported for seriously
or moderately ill infants but some, like noisy or
altered breathing, cough, diarrhea, or irritability,
are commoner in infants who are well or mildly ill.
A recurring theme in the literature about sudden
infant death syndrome is that some infants are
dying unexpectedly from preventable conditions. In
the Department of Health and Social Services study
of postneonatal mortality,2 of the 145 children who
died unexpectedly at home, 36 (25%) had unusual
drowsiness, 15 (10%) had an altered cry, and 26
(18%) were reported to be not feeding normally.
These symptoms are not defined and it is difficult
to know how severe they were but it is possible that
some of those children might not have died if the
importance of their symptoms and signs had been
appreciated.
Those who look after infants must be taught to
recognize the symptoms and particularly the signs
that indicate serious illness. Some, such as
convul-sions and frank blood in the stools, are obvious to
all observers. The ones that are less well recognized,
and yet are very important, are as follows:
drowsi-ness (loss of awareness, alertness, or eye contact
even transiently); bile-stained vomiting; a very low
fluid intake or poor urine output in the last 24
hours; a weak, whimpering, moaning, or
high-pitched cry; obvious retraction of the lower ribs; an
expiratory grunt; and hypotonia.
Individual signs and symptoms are not always
useful in the assessment of an infant’s illness.
Those most predictive for serious illness indicate
an advanced stage of the illness and are not present in all seriously ill infants. It would be preferable to
recognize that an infant is ill before he or she
exhibits such signs. A combination of symptoms
and signs is likely to give a more accurate
assess-ment of an illness. The data presented in this paper
have also been subjected to regression analyses to
determine the combination of symptoms and signs
which have the highest specificity and sensitivity
for grading illness in the first few months of life.
This is the subject of separate papers.”4
ACKNOWLEDGMENTS
This work was supported by the Baby Illness Research Project Appeal of the Foundation for the Study of Infant Deaths, Australian Institute of Health, Ross Trust, Fel-ton Bequests, H. L. Hecht Trust, Percy Baxter Charitable Trust, and the A. Williams Private Fund.
Dr D. Roberton, Dr J. McNamara, and Dr M. Robinson
reviewed the Melbourne case notes. S. Bechervaise, S.
Symptom Definition
Cold hands and feet Noisy breathing Runny nose Sweating
Increased irritability Cough
Feels hot
Pallor
Not feeding normally
Vomiting
Not himself/herself Diarrhea
Abnormal cry Less urine
Breathing difficulty
Decreased activity Drowsy
Jaundice
Projectile vomiting Cyanotic episodes
Apneic episodes
Bile-stained vomit-ing
Blood in stools Convulsion
APPENDIX: DEFINITION OF THE SYMPTOMS
Hands, feet, or limbs have felt cold.
Persistent noises, including mucousy sounds, snuffles, stridor, grunt, or wheeze. Mucus seen over philtrum (not just a blocked nose).
Beads of sweat on forehead, or obviously wet hair when at rest or feeding.
More fractious and difficult to settle than usual.
More than 5 episodes of coughing per day.
Feeling hotter than normal. Looking generally pale.
Taking less fluids or solids, or feeding more slowly than usual. The amount of fluid taken was scored in thirds of normal intake.
Forceful regurgitation of significant quantity of fluid. The number of vomits of more than half the feed was recorded.
Baby has not been his or her usual self.
Excessively fluid motions. If present the number of stools in the last 24 hours was recorded.
An unusual character to the cry.
Fewer wet diapers than usual, or drier diapers than usual. If fewer, the number of wet ones was recorded.
Working harder to breathe, or heaving chest.
Moving arms and legs less than usual.
Less alert than usual. A score was then used which allowed a more objective assessment of drowsiness: “When the baby is awake is he or she (a) always alert, (b) occasionally drowsy, (c) occasionally alert, (d) never alert.”
Yellow skin or sclera.
Vomit which travels more than 45 cm.
Periods of obvious blueness of the tongue and lips. Cessation of breathing for 20 seconds or more. Episodes of green vomiting.
Frank blood mixed with the stool (not streaks). Shaking movements with decreased awareness.
* Symptoms were recorded as present only if they had been present within the previous 24 hours.
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