Introduction

Thyroid storm, also known as thyrotoxic crisis, is a manifestation of hyperthyroidism that is rare but potentially life-threatening.¹ It is characterised by excess levels of circulating thyroid hormones, thyroxine (T4) and triiodothyronine (T3), which have widespread effects throughout the body, leading to numerous, and often severe symptoms. 

Thyroid storm is most commonly associated with underlying thyroid conditions, such as Graves’ disease, and can occur at any age; however, its frequency tends to increase with age.^1,2 

Although thyroid storm can affect individuals of any age, the presentation of symptoms and therefore treatment strategies can differ between paediatric and adult patient populations. Understanding these distinctions is important for timely diagnosis and treatment, as delays can lead to poor patient outcomes. 

This article highlights the key differences in the presentation and management of thyroid storm in children versus adults.

Clinical presentation

Since thyroid storm affects multiple organ systems throughout the body, it leads to a wide range of symptoms that can differ in severity. 

General symptoms that affect both paediatric and adult patients include:^1,3

• Fever
• Tachycardia (abnormally fast heart rate)
• Hypertension (high blood pressure)
• Altered state of mind (e.g., confusion or nervousness)
• Nausea
• Vomiting
• Diarrhoea
• Excessive sweating
• Muscle weakness and extreme fatigue
• Resting tremor (involuntary shakiness)

Differences in symptomatology

Often, the differences in the clinical presentation of thyroid storm between children and adults are not necessarily the symptoms themselves, but rather related to their severity and dominance.

Children often exhibit heightened irritability, heat intolerance, increased appetite, significant weight loss, and hyperactivity.^2,4 Additionally, they generally present with more pronounced gastrointestinal-related (stomach-related) complications, such as vomiting and diarrhoea.⁴ Tachycardia is typically the most prevalent cardiovascular (heart-related) manifestation in younger patients, but is generally less severe than in adults.³

On the other hand, adults are more likely to present with more severe cardiovascular complications, including atrial fibrillation and heart failure, in addition to tachycardia. Neurological complications such as seizures and even coma are more commonly observed in adults. Anxiety and confusion are common in both patient populations, but may manifest more severely in the form of psychosis in adults.⁵

Despite the differences in the symptomatology between paediatric and adult patients, if thyroid storm is left untreated, it can progress to become life-threatening, with severe consequences like multiple organ failure for both patient populations.^1,3,9 

Challenges in diagnosis

The diagnosis of thyroid storm is primarily established by clinical observation, with laboratory tests only able to support a diagnosis.³ Due to the variety of symptoms thyroid storm causes, some of which mimic other conditions like sepsis, heat stroke, and gastrointestinal infections, diagnosis can be challenging for clinicians.¹ 

Although there is an overlap of symptoms between both paediatric and adult patients, the differences in their severity and dominance can impact diagnosis and cause delay. Thyroid storm in children can often be misattributed to hyperactivity disorders or gastrointestinal infections, whereas adults have a higher potential for being misdiagnosed with sepsis, panic disorders, or cardiac conditions.^1,2,10

Management strategies

Thyroid storm requires rapid medical intervention to stabilise the patient, with admission to an intensive care unit is often required.⁶ A combination of medications and supportive measures form the gold standard in treatment.^1,7 Together, these address the different aspects of the condition and stabilise the patient.

Both paediatric and adult patients require a combination of medicines to:

• Block the effects of adrenaline on the cardiovascular system with the help of beta-blockers
• Prevent further thyroid hormones from being made and released into the circulation by antithyroid drugs and iodine therapy
• Reduce systemic inflammation with corticosteroids 

Beta blockers

Propranolol is the most commonly used beta-blocker, which acts to slow the heart rate, lower blood pressure, and help control tremors. 

Esmolol is often used for critically ill patients where stricter control over the heart rate is required. It is also the preferred drug if the patient is at risk of developing bronchospasms (constriction of the airways). 

Paediatric patients generally receive lower doses of beta-blockers to avoid bradycardia (abnormally slow heart rate) and hypotension (low blood pressure). Since adults typically have more severe cardiovascular manifestations, they’ll likely receive a higher dose of beta-blockers than children. 

Additionally, adults may have beta-blockers administered intravenously for a more rapid administration versus orally in children.^1,7

Antithyroid drugs

Methimazole and propylthiouracil (PTU) are the two most commonly used anti-thyroid drugs that inhibit further production of thyroid hormones T4 and T3.^1,7 PTU is the preferred agent; however, it is generally avoided in children as it has a higher risk of hepatotoxicity (liver damage).^2,8 

Adults who are initially given PTU may often transition to methimazole once stable to reduce the risk of liver damage; However, as methimazole is a teratogenic drug (can cause birth defects), it is avoided in pregnant patients.⁷

Iodine therapy

When administered in excessive doses, iodine blocks the release of thyroid hormones into the circulation via a phenomenon called the Wolff-Chaikoff effect. 

Lugol’s solution or saturated solution of potassium iodide (SSKI) are the two commonly used types of iodine therapy in both paediatric and adult patients; however, a lower dose is administered to children based on their weight to minimise adverse effects.⁷

Corticosteroids

Hydrocortisone and dexamethasone are used to treat multiple aspects of thyroid storm. They act to reduce systemic inflammation, stabilise blood pressure and prevent the patient from developing adrenal insufficiency(a condition where the adrenal glands fail to produce the correct levels of essential hormones).⁶ 

Paediatric patients often receive a lower dose of corticosteroids, as long-term use in children can affect growth.^1,7

Supportive measures

General supportive measures further aid patient stabilisation and are implemented in treatment regimens for both paediatric and adult patients.¹

These include:

• Intravascular (IV) fluids to restore and maintain fluid and electrolyte levels
• Cooling blankets to counteract the effects of hypermetabolism
• Acetaminophen (paracetamol) to control fever
• Oxygen therapy if the patient is experiencing respiratory distress (severe cases)
• Sedatives if the patient is agitated or in distress (severe cases)

FAQs

Why do children require lower doses of medication?

There are several reasons why a child would receive different medication doses from an adult. Dosing is often based on the bodyweight of the patient, e.g., mg/kg or body surface area (BSA). Since children are smaller in size than adults, giving the same dose could lead to dangerous side effects, like toxicity. 

Additionally, because children are still developing, their organs tend to be more sensitive to medications, meaning a lower dose is sufficient to achieve the required effect. For this reason, clinicians typically use the lowest effective dose in children to minimise adverse effects.^11,12

Summary

Thyroid storm presents similarly in children and adults; however, differences in the dominant symptoms and their severity raise challenges in diagnosis. The management of thyroid storm is principally the same in both paediatric and adult patient populations; however, important considerations regarding drug selection and dosage vary, requiring clinicians to tailor treatment regimens. 

Children generally require lower doses of beta-blockers and corticosteroids to minimise adverse effects. In adults, more aggressive treatment is often warranted (including higher doses), as well as the need for close cardiac monitoring.