Endemic goitre and iodine deficiency


– Goitre is an enlargement of the thyroid gland. Endemic goitre occurs in iodine-deficient areas. Goitre can also be caused or aggravated by the regular consumption of goitrogens such as manioc, cabbage, turnips, millet etc.

– Goitre is an adaptive process: iodine is essential for the production of thyroid hormones; iodine deficiency impairs thyroid hormone synthesis; to compensate, the thyroid gland increases in volume. Thyroid function usually remains normal.

– As well as the development of goitre, iodine deficiency in pregnant women has serious consequences for the child (foetal and perinatal mortality, physical and mental retardation, cretinism). These risks must be prevented by providing iodine supplementation in iodinedeficient areas.

Clinical features

– The WHO proposes a simplified classification based on the significance of goitre:

Group 0: normal thyroid, no palpable or visible goitre
Group 1: enlarged thyroid, palpable but not visible when the neck is in the normal position
Group 2: thyroid clearly visible when the neck is in the normal position

– Possible mechanical complications (rare): compression, deviation of the trachea or of the oesophagus.

Prevention and treatment

The objective of prevention is to reduce the consequences of iodine deficiency in neonates and children. Supplying iodised salt through national programmes is the recommended method of prevention.

For prevention in populations living in iodine deficient areas where iodised salt is not available and for curative treatment of patients with goitre: use iodised oil, according to national protocols. For information (according to the WHO):


Population

Iodised oil PO
once yearly
(190 mg capsule)

Children under 1 year

1 capsule

Children from 1 to < 6 years

2 capsules

Children from 6 to 15 years

3 capsules

Pregnant or lactating women
or women of childbearing age

2 capsules

Curative and preventive single-doses are the same. Oral treatment is preferred. The target populations are pregnant and breastfeeding women, women of childbearing age and children.

In children, goitre disappears after several months. It disappears more slowly (or never) in adults despite restoration of normal thyroid function in 2 weeks. Surgery is only indicated for patients with local mechanical dysfunction.