Makindo Medical Notes

Endemic goitre was prevalent in the population of Derbyshire in the UK for many centuries until it declined from the 1930s. Iodine is a trace element in the human body and is absorbed through the gut as iodide, the chemically bound form of iodine. The iodine content of food depends on the iodine content of the soil in which it is grown. Iodine in the soil is often leached out by repeated flooding and glacial activity and carried to the sea, making seawater, seaweed, and marine fish rich sources of iodine.

About

• Iodine deficiency goitre is the most common cause of goitre worldwide.
• It can lead to cretinism in infants.
• Goitre reflects chronic iodine deficiency, leading to thyroid enlargement.
• Goitre is defined as an enlarged thyroid, and the WHO describes it as "a thyroid gland whose lateral lobes have a volume greater than the terminal phalanges of the thumbs of the person being examined".

Geography

• Historically called "Derbyshire neck" in the UK due to its prevalence in the region.
• Endemic in areas such as the Netherlands, Western Pacific, India, Southeast Asia, Russia, and parts of Africa.
• Occurs in populations with an iodine intake of less than 10 mcg per day.

Aetiology

• Chronic borderline hypothyroidism can lead to raised TSH levels, causing thyroid growth.

Clinical Features

• The patient may be either hypothyroid or euthyroid.
• Neck mass, stridor, or discomfort from the enlargement may be present.

Grade Characteristics

• Grade 0: No palpable or visible goitre.
• Grade 1: A goitre that is palpable but not visible when the neck is in a normal position. Nodules in a thyroid that is otherwise not enlarged fall into this category.
• Grade 2: A visible swelling in the neck that is consistent with an enlarged thyroid gland when palpated.

Investigations

• Thyroid Function Tests (TFTs): May indicate hypothyroidism.
• Thyroid ultrasonography to assess the gland's structure.
• CT scans may be useful in complex cases.

Management

• Public health measures, such as adding iodine to salt, have been successful in managing iodine deficiency.
• Neonatal screening for hypothyroidism is essential to prevent developmental issues in infants.
• Pregnant women are particularly vulnerable to iodine deficiency, with the fetus at risk of developmental problems if iodine levels are low.

References

• WHO on Endemic Goitre