Dr Swati Joshi,
Lecturer (Endocrinology and Epilepsy)
B J Wadia Hospital for Children,
Mumbai.
Growth is an important objective parameter of general health of a child.
Short stature is a common problem encountered by practicing pediatricians.
The etiology of short stature ranges from normal variants like familial
short stature (FSS) & constitutional growth delay (CGD) to pathological
conditions like endocrine & systemic disorders. Fortunately, the normal
variants form the commoner causes and can be suggested by basic tools
like anthropometric data and bone age. However, the distinction between
normal & abnormal growth can be difficult at times
Short stature may sometimes be the only obvious manifestation of endocrine conditions & systemic diseases
Definition:
A child is
considered short if :-
-
His height is less than 3rd percentile or 2 standard deviations below the mean height for that age.
-
Even if the height is within normal percentiles but growth velocity is consistently below 25th percentile over 6-12 months of observation.
-
If the patient is excessively short for the mid-parental height, though his absolute height may be within the normal percentiles.
Useful point to note : 80% of children with height less than 3SD below mean have pathologic Short Stature whereas 80% of children with height less than 2SD usually have normal variant Short Stature.
Important terminologies & facts while evaluating Short Stature:
- Height Age - The age at which the patient's height is at the 50th percentile.
- Bone age - Refers to the age at which the skeletal maturation shown in patient's radiographs is normally attained. Greulich Pyle charts are the most commonly used method, which examines the epiphyseal maturation of the hand & wrist.
- Mid-parental height (MPH):- The child's probable inherited growth potential can be estimated by mid-parental height percentile.
| MPH range for boys = (mother's height+13cm)+ father's height + 8cm |
| 2 |
| MPH range for girls = Mother's height + (father's height- 13cm) + 8cm |
| 2 |
-
Growth velocity / Height velocity - Observation of a child's height over a period of time or height velocity is the most important aspect of assessment of Short Stature. Since linear growth in children occurs in small episodic increments, there are inherent inadequacies in measuring linear growth. Therefore, determination of height velocity requires at least 6 months of observation.
Normal Growth velocities at different ages-
Age |
Average Growth Velocity / Year. |
| 1st year |
25cm |
| 2nd year |
12-13cm |
| 3rd & 4th year |
6-7 cm |
| 5 years- till onset of puberty |
5cm/year |
(The Growth Velocity may fall to as low as 4cm/year just before the pubertal spurt)
A child's growth curve follows along the same channel or percentile from 2-9 years of age. The linear growth of normal infants (upto 8 months) may move to higher or lower percentile due to physiologic shift from intrauterine influences to the child's inherent growth potential. Crossing channels during puberty may be due to differential onset & extent of the pubertal growth spurt.
Thus, excepting infancy, subnormal growth velocity is the hallmark of postnatal pathologic Short Stature.
-
Growth charts - Various growth charts are available for monitoring the heights of which Tanner & Davis charts are widely used. WHO has adapted the NCHS growth charts as reference standards.
In India, the ICMR based on their multicentric study, have developed reference standards for growth. This study was predominantly done in lower socioeconomic sections, therefore reflects the growth characteristics of only these sections.
Data from study by Agarwal et al (1994) have provided reference data for well nourished children.
Etiology:
| Systemic diseases |
Skeletal dysplasias
|
- Chronic Anemia
- Chronic renal failure
- Renal tubular acidosis
- Chronic Asthma
- Congenital heart disease
- Chronic infections
- Malabsorption
- Chronic liver disease.
Malnutrition
Endocrine disorders
- Growth hormone deficiency
- Hypothyroidism
- Cushing syndrome
- Diabetes mellitus
- Diabetes insipidus (due totumors, neonatal insult)
- Hypopitutarism
- Hypogonadism.
Intrauterine growth retardation (IUGR)
Genetic syndromes - common examples:
- Turner's syndrome
- Noonan's syndrome
- Russel Silver syndrome
- Seckel's syndrome
- Down's syndrome
Inborn error of metabolism
Psychosocial dwarfism
Idiopathic Short Stature
|
|
Clinical Evaluation:
While assessing a child with Short Stature, we should try to answer the following questions:
- Is the child is really short?
(Children may be referred to a clinic with a mistaken view of their height.) Accurate measurement of height is essential to know whether the child is short. Also because small fallacies in height measurements may get amplified while calculating growth velocities, height should be measured on stadiometer (or similar equipment). Shoes are to be removed & patient is made to stand straight with heels, buttocks, back & occiput touching the vertical support, the head being positioned so that Frankfurt plane (line joining the inferior margin of the orbit to external auditory meatus) is parallel to the ground.
Supine length is taken in children below 2 years of age with an infantometer.
- Is the child growing slowly?
Serial height measurements at 3-6 monthly intervals should done to know the annual growth velocity.
Retardation of growth velocity is the hallmark of postnatal pathologic short stature.
- Is he a normal variant Short Stature?
-
Familial short stature (FSS)
A child who has FSS is short for general population but is normal for the family pedigree. The birth length tends to be small. The child's projected adult height falls within the mid parental height range. The bone age & growth velocity are normal. Growth proceeds along a channel below but parallel to the 3rd percentile curve. The final height of such a child will be short.
-
Constitutional growth delay (CGD)
Typically,
the child with CGD, is a normal looking child who is described as a 'late bloomer'. There is often a family history of father
being short as a child & experiencing a late pubertal spurt.
The bone age is delayed & corresponds to the height age. The
birth length is normal but typically slows down to fall below 5th
percentile in the first three years of life. Although puberty is delayed,
the final adult height and sexual development are normal.
Salient features of Normal Variant Short Stature:
| |
FSS |
CGD |
Sex |
- |
Commoner in boys |
Birth Height |
Less |
Normal |
Family History |
History of short stature -positive |
Delayed puberty especially in father |
Growth Velocity |
Growth Velocity |
Growth Velocity normal for bone age. |
Bone Age |
Normal |
Slight delay / BA = HA |
Final adult height |
short |
Normal |
- Are there any specific stigmata/ clues on history & examination?
A thorough clinical assessment often gives clues towards etiology. These coupled with basic screening tests can lead us towards specific tests to be carried out to arrive at a diagnosis.
The following points should be sought for in the clinical evaluation:
HISTORY |
ETIOLOGY |
| History at Presentation |
- Fever, weight loss, anorexia
|
Chronic infection |
- Chronic diarrhea/ bulky frothy stools
|
Malabsorption |
|
Asthma, TB, CHD |
- Headache/ vomiting/ diplopia
|
Intracranial tumors (Craniopharyngioma)
|
|
Diabetes insipidus, mellitus, RTA |
|
Cushing's syndrome |
- Constipation, delayed milestones, lethargy
|
Hypothyroidism |
| Birth History |
|
IUGR, dysmorphic syndromes |
- Birth asphyxia, breech presentation, Neonatal hypoglycemia, icterus
|
Growth Hormone Deficiency |
| Dietary History |
- Poor protein caloric intake
|
Malnutrition / Rickets |
| Family History |
- Short stature in sibs/ parents/cousins
|
FSS |
|
CGD |
| Psychosocial |
|
Psychosocial dwarfism |
EXAMINATION |
ETIOLOGY |
- Increased respiratory rate
|
CHD, Asthma,
IEM (acidosis) |
|
Cushing syndrome, CNS tumors, CRF |
|
Chronic Anemia, CRF, Hypothyroidism |
|
Nutritional Vit D def,
RTA |
- Disproportionate Body proportions
|
Skeletal dysplasias, Rickets |
- Decreased Weight for height
|
Malnutrition |
- Frontal bossing, midfacial crowding, micropenis, truncal obesity
|
Growth hormone deficiency |
- Coarse skin, delayed relaxation of jerks, + goitre, bradycardia
|
Hypothyroidism |
- Papilledema, visual field defects
|
Tumors- craniopharyngioma |
- Central obesity, striae, hypertension
|
Cushing syndrome |
- Female with webbed neck, Cubitus valgus, shield chest
|
Turner syndrome |
- Male / female with triangular facies, webbed neck, ptosis, pectus excavatum & pulmonary stenosis
|
Noonan Syndrome |
- Small triangular facies, hemihypertrophy, clinodactyly
|
Russel Silver syndrome |
- Bird headed dwarfism with small face, large eyes, microcephaly & micrognathia
|
Seckel syndrome |
- Brachycephaly, simian crease, large tongue
|
Down's syndrome |
Investigations:
If the clinical assessment is suggestive of a particular etiology for short stature, one should proceed towards doing tests to confirm the diagnosis. However, if there are no clues on history/ examination, which is often the case, certain screening tests are advisable in these patients.
The following algorithm would be useful for future evaluation:
Apart from specific treatment, according to the under lying etiology, it is important to counsel parents. Children with short stature can have psychological stress due to negative comments from relatives, peers at school etc. The parents must be advised to bring out positive aspects of child's personality & not to over emphasize the abnormalities of stature. The importance of diet and exercise should also be conveyed so as to achieve the maximum potential.
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