Overview

What is croup?

Croup is a respiratory condition caused by infections of the upper airway, most commonly occurring in young children below 5 years old. The symptoms are usually mild, and patients can recover by themselves. After infection, inflammation occurs in the trachea (windpipe), larynx (voice box), and bronchi (parts of the lung), leading to a barking cough (sounds like a seal’s bark) and inspiratory stridor.¹

What is laryngitis?

Laryngitis is inflammation of the larynx, also known as the voice box. It can be a sudden or a long-term occurrence, called acute or chronic laryngitis. For acute laryngitis, mild symptoms normally last for 3 to 7 days and then self-resolve, whereas chronic conditions last over 3 weeks.²

Causes

Croup

Croup is primarily caused by a viral infection, however, some cases are caused by bacteria.¹

• Viral infections: The parainfluenza virus plays a key role in croup. Other viruses are influenza A and B, measles, adenovirus, and respiratory syncytial virus (RSV)
• Bacterial infections: Less commonly, bacteria such as Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis

Laryngitis

One difference between laryngitis and croup is their causes. Laryngitis can be caused by both infectious and non-infectious factors.²

Infectious causes

For infectious causes, laryngitis is similar to croup, whereby infection occurs in the upper respiratory tract. Infectious causes include:^2,3

• Viral infections: Common viruses include rhinovirus, parainfluenza virus, respiratory syncytial virus, coronavirus, adenovirus, and influenza
• Bacterial infections: Commonly found in laryngitis are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis
• Fungal infections: Rare, and usually seen in immunocompromised patients or those using inhaled corticosteroids, often presenting as chronic laryngitis

Non-infection causes

Environmental factors 

Smoking, irritants or allergens can induce inflammation, and exposure in the long term can lead to chronic laryngitis. Cigarettes consist of various chemical components that can trigger the voice box's inflammation and swelling. Furthermore, pollutants can dry the airway tracts, which may result in difficulty producing voice and discomfort or pain when speaking.⁴

Vocal strain

If you overuse or misuse your voice, or have trauma, you can develop laryngitis. For example, symptoms can be seen after a day of too much shouting. This also happens to singers, especially those performing more often or more intensely without appropriate voice or singing training.²

Medical conditions

Gastro-oesophageal reflux (GORD) can affect the voice box and cause laryngitis. Additionally, patients with asthma can develop laryngitis as steroid inhalers can irritate the voice box and increase the risk of fungal infections. As asthma often causes coughing, it can cause injury to vocal cords, resulting in symptoms of laryngitis.⁵

Age group

Croup

Croup typically affects young children aged between 6 months and 3 years and is more common in male children (about 60%).⁶

Laryngitis

Laryngitis can affect individuals of all ages. It typically presents in adults aged 18 to 40, and particularly those who use their voice extensively.²

Symptoms

Croup

After children get infected, the windpipe, the airways to the lungs and the voice box become swollen as their immune system fights against the infection. It then causes partial airway blockage, leading to difficulty in breathing and a unique, turbulent, noisy airflow. Symptoms of croup include:¹

• Barking cough
• Stridor: A unique, abnormal, high-pitched and wheezing sound caused by turbulent airflow
• Hoarseness: Changes in the pitch or voice quality, which sound weak or scratchy
• Mild fever 
• Difficulty breathing

Laryngitis

For acute laryngitis, symptoms start suddenly and become worse after around 2 or 3 days. Without treatment, the symptoms may remain for a week or more. Symptoms include:²

• Hoarseness or loss of voice
• Discomfort or pain in the throat
• Dry throat
• Dry cough
• Mild fever (occasionally)
• Throat clearing
• Pain or difficulty swallowing

Diagnosis

Croup

• Clinical examination will be performed to listen to stridor and cough
• X-rays for identifying the characteristic steeple sign in severe cases^{1, 7}

Laryngitis

• Doctors usually evaluate a patient's history and physical examination²
• Clinical examination to look at your throat and listen to your voice to check for signs of inflammation and hoarseness. This involves observing for any swelling or redness of the vocal cords
• Laryngoscopy may be performed if further investigation is needed. A small, flexible tube with a camera is inserted through the nose or mouth to see and assess the voice box and vocal cords. This is to evaluate the severity of the laryngitis

Treatment

Croup

Humidified air

This can be used at home. For example, using mist from a humidifier or using steam generated by running hot water from the shower while children are sitting in the bathroom with their parents. It should be noted that hot steam humidifiers should be avoided as they can burn your child’s skin.

Steroids

Corticosteroids, such as dexamethasone, can help symptoms, speed up recovery, and decrease the chance of coming back to and the time to stay in the hospital.⁷

Nebulised adrenaline

Adrenaline may be used for the treatment of severe cases. It can improve symptoms within 30 minutes, with its effects lasting up to 2 hours.⁸

Antibiotics

As croup usually involves viral infections, antibiotics have less room for croup treatment. They are used in primary or secondary bacterial infections.¹

Laryngitis

Laryngitis often clears up within a few days to a week. Treatment choices depend on the symptoms and their severity.²

Resting the voice

This is an important factor. If you keep using your voice, it makes it more difficult for the voice box to fully recover, or results in delayed recovery. It is best to rest your voice completely, however, this is hard to do. It is therefore recommended that patients should speak in a normal tone but at a low volume without whispering or speaking loudly.²

Diet control

Control of your diet is recommended in gastro-oesophageal reflux disease (GORD). You should avoid foods or drinks that irritate the stomach, such as caffeinated drinks, spicy food, fatty food and peppermint. Moreover, you should adjust your eating habits, including having meals at least 3 hours before lying down.⁷

Humidified air

Increasing moisture in the air can reduce dryness of the upper airway and remove secretions.²

Avoiding irritants

Patients with laryngitis should avoid smoking or alcohol because smoking can delay time to recovery.² 

Antimicrobials

If bacterial infections is confirmed, antibiotics may be needed. Evidence more strongly supports prescribing antibiotics for patients with high-risk or severe symptoms.² If patients have fungal laryngitis, oral antifungal medication will be used for a 3-week period. However, confirmation of fungal infection by examination and/or culture is required before receiving treatment.

Mucolytic agents

Can be used for clearing mucus.²

Anti-reflux medications

Medications that suppress acid production can be useful for laryngopharyngeal reflux.²

Prognosis

Croup

Croup is generally self-limiting and resolves by itself. The symptoms usually improve within a week, but can last occasionally up to two weeks.⁴ Treatment is considered in mild and severe cases. The prognosis of croup is mostly excellent, however, croup can have rare complications such as bacterial tracheitis or pneumonia, which can be life-threatening.¹

Laryngitis

Laryngitis, especially acute laryngitis, is typically self-limiting and symptoms normally last for 3 to 7 days. However, chronic laryngitis may require ongoing management to control symptoms or prevent flare-ups. This includes lifestyle modification, voice management, and medication to reduce inflammation and treat other associated conditions.²

Potential complications include vocal cord damage. If left untreated, laryngitis can lead to permanent vocal cord damage, and speech therapy will be required to help resolve this condition.²

Prevention

Croup

Hygiene practices

As infection normally spreads through contact and airborne, paying attention to hygiene is necessary to reduce infectious transmission. To prevent the contact or spreading of the croup virus or bacteria, you should wash your hands regularly, especially before eating or touching your mouth, nose or eyes, and avoid sharing dishware or other items with a person who has croup. These tips can reduce exposure to respiratory viruses.¹

Vaccination 

Currently, no vaccine covers all types of viruses in Croup. There are vaccines against influenza and COVID-19, and it has been recommended for a child older than 6 months to be vaccinated.

Laryngitis

• Avoiding overuse of the voice: If you overuse your voice, such as excessively talking, shouting or singing, you should rest your voice properly and consider voice therapy
• Staying hydrated: Keep drinking plenty of water to moisten your vocal cords and reduce irritation
• Avoid irritants such as smoking or pollutants that can irritate your vocal cords, which may lead to laryngitis
• Keeping good hygiene practices by washing your hands regularly and avoiding close contact with people who are unwell, as this can increase the risk of infections²

Summary

Croup and laryngitis are both conditions that affect the upper airway, but they differ significantly in their causes, symptoms, affected age groups, and treatments.

Croup is most common in young children, particularly those aged 6 months to 3 years. It is primarily caused by viral infections and is recognised by its distinctive barking cough, stridor, and breathing difficulties. Croup is usually self-limiting, but moderate to severe cases may require treatment with steroids or nebulised adrenaline.

Laryngitis, in contrast, can affect people of all ages and has a wider range of causes, including viral or bacterial infections, environmental irritants, vocal strain, and medical conditions such as GORD. Its hallmark symptoms include hoarseness, sore throat, and loss of voice. Treatment often focuses on voice rest, hydration, and addressing the underlying cause, with antibiotics or antifungals prescribed only when necessary.

Understanding the differences between these two conditions is important for proper diagnosis, management, and prevention. While both conditions are usually mild, timely intervention can help reduce complications and promote faster recovery.