Short stature is usually physiological, and is due to reduced genetic potential or maturational delay (slow physical development). Fall-off in growth is much more concerning as it suggests a pathological cause. Short stature can cause social difficulties, particularly for adolescent boys, and occasionally psychological counselling is required.
Constitutional or Familial Short Stature
Short parents tend to have short children. In this case the history and physical examination are normal, and the bone age appropriate for age. Reassurance is often all that is needed. Prescribing growth hormone in children with physiological short stature is controversial and probably has little effect on the child’s final adult height.
Children with maturational delay are often called ‘late developers’ or ‘late bloomers’. These children are short and reach puberty late. Their final height depends on their genetic constitution, and may be normal. There is often a family history of delayed puberty and menarche, and the bone age is delayed. Most families simply require reassurance that final height will not be so affected. Sometimes, teenage boys find the social pressures are so great that it is helpful to trigger puberty early using low doses of testosterone, so causing an early growth spurt. This treatment does not have an effect on final height.
The most common causes of hypothyroidism are Hashimoto’s autoimmune thyroiditis, which is more common in girls, and hypothyroidism secondary to hypopituitarism. A lack of thyroid hormone has a profound effect on growth, and short stature is often the presenting sign. Other features include a fall-off in school performance, constipation, dry skin and delayed puberty. Low thyroxine (T4) and high thyroid stimulating hormone (TSH) levels are found on investigation, along with antithyroid antibodies if the cause is autoimmune. Treatment with thyroid hormone is lifelong. Parents are often alarmed when their placid, hypothyroid child is transformed into a normal, active teenager. The prognosis is good.
Rarer Hormonal Problems
Cushing’s syndrome and disease are extremely rare in childhood. However, growth suppression from exogenous steroids (e.g. high-dose inhaled steroids for asthma) is not uncommon. When children require long-term high-dose oral steroid therapy, the deleterious effect on growth is reduced by giving steroids on alternate days.
Growth hormone deficiency is a rare cause of short stature. It may be idiopathic or may occur secondary to pituitary tumours or cranial irradiation. It may be accompanied by deficiency of other pituitary hormones. The diagnosis is made by growth hormone testing, and brain imaging is needed to identify any underlying pathology. Treatment involves daily subcutaneous injections of synthetic growth hormone.
Any chronic illness can cause stunting of growth. However, chronic illnesses rarely present as short stature as the features of the illness are usually all too evident. Chronic conditions that present with poor growth before other clinical features become obvious include inflammatory bowel disease, coeliac disease and chronic renal failure.
Turner’s syndrome or gonadal dysgenesis is an important cause of short stature and delayed puberty in girls. It is caused by the absence of one X chromosome, although mosaicism also occurs. The gonads are merely streaks of fibrous tissue.
At birth, Turner babies often have webbing of the neck and lymphoedematous hands and feet. In childhood, short stature is marked and girls often have the classic features of webbing of the neck, shield-shaped chest, wide-spaced nipples and a wide carrying angle. Some girls are only diagnosed in adolescence when puberty fails to occur. Growth can be promoted by small doses of growth hormone and oestrogen in childhood. Puberty has to be initiated and maintained by oestrogen therapy. Despite treatment, women with Turner’s syndrome are usually short. As a result of recent advances in infertility treatment, a few women have become pregnant through in-vitro fertilization (IVF) with donated ova.
- A good history and physical examination identify most pathological causes of short stature.
- Focus on looking for signs of intracranial pathology, hormone deficiency, chronic illness and gastrointestinal symptoms.
- Relate the child’s height to the parents’ heights.
- Identify any emotional and social consequences of being short.