Various causes drive chronic cough in children, prompting different treatment

Key takeaways:

• Most cases are benign and resolve spontaneously.
• The most common causes are post-infectious, asthma or protracted bacterial bronchitis.
• Greater provider awareness and better guidelines are needed.

PARK CITY, Utah — Chronic cough has a variety of causes in children, with broad options for treatment, according to a talk at the Association of PAs in Allergy, Asthma and Immunology Annual Allergy, Asthma & Immunology CME Conference.

These vague and complicated cases can be troubling for parents, Amanda Michaud, DMSc, PA-C, AE-C, physician assistant with Family Allergy & Asthma Consultants, said during her presentation.

“These parents are really frustrated, especially since COVID,” said Michaud, who also is secretary of the Association of PAs in Allergy, Asthma and Immunology. “It can be challenging.”

Primary causes, treatments

Chronic cough refers to cough that has lasted more than 4 weeks in children. Initial assessments should include a detailed history and physical exam, and treatment should target a specific cause when one is determined.

Amanda Michaud

“If no specific pointers are detected, just like adults, we’re going to get a chest X-ray,” Michaud said, adding that children should complete spirometry as well if possible.

If the results of these tests are normal, 4 weeks of observation should follow, Michaud said.

“The vast majority are benign and resolve spontaneously,” Michaud said. “A 4-week waiting period is worth instituting before doing any pharmacologic therapy.”

The three most common causes of chronic cough in children are post-infectious cough, asthma and protracted bacterial bronchitis (PBB).

“Post-infectious cough will present typically after a viral illness. It will be nonspecific. They won’t be able to describe much about it besides that it seems to be dry. There are no specific pointers there,” Michaud said.

Chest X-rays and spirometry will be normal with post-infectious cough, Michaud said, adding that it is appropriate to monitor and not treat these cases, allowing them to resolve.

“But there’s still a huge quality-of-life impact on the kiddo, at school or in the day care or wherever, and in the parents having to deal with it,” she said.

Environmental exposures and irritants such as smoke may play a role in these cases, Michaud advised, but they usually spontaneously resolve.

Isolated cough is rarely a symptom with asthma, Michaud said, because asthma usually comes with other symptoms such as exertional dyspnea, bilateral recurrent wheeze, or a personal or family history of atopy.

Spirometry may indicate a reversible obstructive pattern, or a chest X-ray may indicate bilateral hyperinflation. Fractional exhaled nitric oxide testing will support diagnoses among children who can handle it as well.

“With these kiddos, just like with the adults, we follow treatment guidelines for asthma like we would do with our normal asthma patients and just see how they do,” Michaud said.

Even when spirometry and the chest X-ray are normal, Michaud said low-dose inhaled corticosteroids can be prescribed for 2 to 4 weeks. Doses can be increased in the short term if outcomes are unclear.

“Bronchodilators can be added as well,” she said.

But if there is no change in symptoms after 2 to 4 weeks, Michaud said, asthma is extremely unlikely.

“So, take them off the medicine,” she said. “It will likely go away.”

However, PBB is very common as well as overlooked and underdiagnosed, Michaud said.

“These kiddos will have a wet cough. That’s the main characteristic here. And it will be more than 4 weeks,” she said. “That cough will resolve after 2 to 4 weeks of appropriate antibiotics.”

These cases have no other underlying causes, Michaud said.

“We’re still doing chest X-rays on these patients. We’re still doing spiros, so we’re ruling out some other things,” she said.

PBB is most common in younger children, aged 1 to 5 years.

“These kiddos look great, otherwise healthy,” Michaud said. “You might hear some of that rattle, that congestion in the chest. The chest X-ray will classically show peribronchial thickening in a lot of these patients.”

Treatment usually involves a combination of amoxicillin and clavulanate for 2 to 4 weeks, although trimethoprim and sulfamethoxazole are alternatives for patients who report a penicillin allergy.

“But we all know they’re probably not really allergic to penicillin, so make sure you work that out too,” Michaud said.

Additionally, Michaud said physicians should be aware that children with PBB are at an increased risk for bronchiectasis, especially after numerous infections.

Other conditions

Chronic cough may involve other factors as well, Michaud said.

“It’s important to just be aware of these things and refer them to the appropriate provider if needed,” she said.

Controversy surrounds whether upper airway cough syndrome and rhinosinusitis are causes of chronic cough in children, Michaud said, although suspected cases can be treated with intranasal corticosteroids and antihistamines.

“See how they do,” Michaud said.

Cough associated with chronic sinus disease in children tends to be related to PBB, based on the unified airway hypothesis, Michaud said.

“It’s tough sometimes. We get people that say, ‘I feel like it’s coming from the sinuses.’ They’re complaining of sinus symptoms. And yet I tell them, ‘I think it’s PBB,’” Michaud said.

“They see bronchitis, and they know that refers to the lungs, so we just make sure we explain that it can still be related to these patients, and so they’ll respond to the antibiotics,” she said.

Gastroesophageal reflux disease (GERD) is an uncommon cause of chronic cough in children aged younger than 15 years unless aspiration is present, Michaud said. Guidelines do not recommend anti-GERD therapy for children with chronic cough when no other gastrointestinal symptoms are present.

But when GI symptoms are present, Michaud said, medication for 4 to 8 weeks is recommended.

“Lifestyle modifications could be helpful for them as well,” she said.

Infections are a more common cause of chronic cough, Michaud said. Up to 20% of children who have chronic cough have had a recent pertussis infection, even though most of these children were vaccinated, she continued.

“We just see this often in the community,” Michaud said. “Consider that, especially if there’s that typical pattern of that paroxysmal cough, retching or vomiting.”

Inspiratory whooping and a history of contact may indicate pertussis as well.

“You can test for this,” she said. “That obviously can be helpful, but sometimes you don’t capture the results that we are looking for.”

Mycoplasma, which lasts for an average of 39 days, also can cause chronic cough, although Michaud called treatment during its chronic stage is controversial too.

“I’ll typically treat, because these patients are again frustrated and it’s affecting their quality of life,” Michaud said. “So, if you put them on a macrolide or something like that, some studies say it can be beneficial, some studies say they don’t do anything, and we need more data here.”

Also known as tic cough, somatic cough disorder often sounds brassy or like barking. It usually involves a single, repetitive cough.

“A lot of these patients have cough all day long, except when they’re sleeping,” Michaud said. “And it is like every 5 seconds. It’s very disruptive.”

Medication should be avoided, Michaud said. Instead, treatment strategies include the art of suggestion, as physicians walk patients through attempts to hold their cough. The way physicians calmly verbalize these instructions is important, she added.

“Hey, try to hold your cough for a minute. Try to hold your cough for 2 minutes. Wow, you’ve gone 2 minutes. You really have control of this cough,” Michaud suggested.

“When you get to 5 minutes and they can hold a cough for 5 minutes, most studies say that cough will never come back, which is incredible,” she said.

Tracheomalacia occurs when the rigidity of the tracheal or mainstem bronchial cartilage is inadequate. Increased irritation and reduced mucus clearing cause bouts of cough that present nocturnally and sound wet. It can be worsened with exercise as well.

“A lot of these patients have been seen by other specialists,” Michaud said.

Bronchiectasis involves a chronic or recurrent wet or productive cough. Etiologies can vary, although Michaud called primary immunodeficiency disorders and cystic fibrosis the most concerning. Foreign bodies and post-infectious and post-transplant cases are possible too.

“These patients will have other symptoms usually as well, and they need to be seen by the appropriate providers to manage those conditions,” Michaud said.

Inhaled foreign bodies are most common in children aged younger than 5 years, with a cough that initially may be dry but usually is wet. Cough begins after a choking episode. Chest exams reveal asymmetrical breath or focal sounds with a unilateral low-pitched wheeze. Chest X-rays may indicate unilateral hyperinflation.

“You might be able to see the foreign body on X-ray, but not always,” Michaud said.

These patients should be referred for bronchoscopy immediately, she said.

Improving care

There are many unmet needs when it comes to chronic cough in children, Michaud said, such as provider awareness, evidence-based guidelines, and understanding of the multiple dimensions of chronic cough and cough endotypes.

“We are deviating from the guidelines substantially when it comes to chronic cough, and it’s not just us,” Michaud said. “It’s the urgent cares, primary care, pediatricians. Everyone needs to be aware of these guidelines.”

Also, Michaud said, there is a need for high-quality double-blind randomized controlled trials evaluating treatment modalities, including specific studies on chronic cough instead of separate diseases, as well as better therapies.

“We need to learn more about specific underlying pathology,” she said.