Primary ciliary dyskinesia (PCD): symptoms, diagnosis and treatment

Cilia are microscopic hair-like structures that line the airways, the sinuses, the middle ear and some other parts of the body. In a healthy airway they beat in a coordinated wave, carrying mucus together with trapped dust and bacteria towards the throat. Royal Brompton and Harefield hospitals describes this wave-like motion as an essential primary defence barrier.

In PCD the cilia either do not move at all or move in a disordered, ineffective way. Cambridge University Hospitals explains that unwanted particles are not cleared from the lungs and nose, which puts people with PCD at greater risk of recurrent respiratory infections. Over time, repeated infection can damage the airways and lead to bronchiectasis, so early diagnosis and consistent treatment matter.

Cambridge says symptoms vary with age. Newborns and infants often present with respiratory problems at birth, such as a runny nose and nasal congestion, which remain constant over time. A child may have a persistent moist-sounding cough and constant coughs and colds. Rarer associations include congenital heart disease and gastro-oesophageal reflux.

Royal Brompton adds that many patients have significant upper airway and ear problems, including glue ear, where the middle ear fills with fluid, which can lead to poor hearing, delayed speech and difficulties at school. Because it can look like exaggerated forms of common childhood illnesses, such as a runny nose, ear infections and frequent cough, it can be difficult to diagnose.

• A wet cough that is present every day, not just with colds.

• A permanently blocked or runny nose from infancy.

• Repeated ear infections or glue ear and hearing difficulty.

• Chest infections, and in time bronchiectasis.

• Chronic sinusitis in older children and adults.

• Situs inversus, where organs are a mirror image of normal, in about half of patients.

• Fertility problems, because the sperm tail is a cilium and the fallopian tubes are lined with cilia.

A consistent history of symptoms suggestive of PCD is the starting point. Cambridge describes a nasal nitric oxide test as a screening test for children over 8 who can blow into a small machine through the nose; if the result is not normal, or if the child is younger or unable to do the test, they need to visit a PCD specialist centre.

At the specialist centre a sample of cilia is taken by gently brushing the inside of the nose, and the sample is examined under a high-power video microscope. Royal Brompton says the disease is often much more difficult to diagnose than cystic fibrosis. A GP, paediatrician or respiratory specialist can refer to one of the national centres.

Royal Brompton says PCD lung disease is managed in a very similar way to any form of bronchiectasis, including cystic fibrosis. The mainstays are airway clearance with daily physiotherapy, nebulisers and other techniques, and antibiotics to treat infections, sometimes over long periods. On occasion patients are admitted for intravenous antibiotics, intense physiotherapy and bronchoscopy when other measures are not improving symptoms and lung function.

Cambridge explains that regular chest physiotherapy helps clear mucus that would otherwise congest the airways, that simple techniques can be taught by a physiotherapist and performed at home, that antibiotics are important to prevent lung damage and are usually taken long term, and that regular reviews with sputum samples or cough swabs are used to choose appropriate antibiotics.

At present there is no cure and treatment will be necessary for life, according to Cambridge. It adds that life expectancy is not felt to be altered if treated appropriately, although it may be reduced if lung disease is allowed to progress untreated.

Fertility can be affected. Cambridge notes that boys tend to be infertile and that girls may experience more problems with pregnancy than the general population, and Royal Brompton explains the cilia-related reasons. Fertility specialists can advise on options.

PCD is inherited in a recessive pattern, which means the faulty gene must come from both parents, who are usually unaffected carriers. Cambridge sets out the chances for each pregnancy as a one in four chance of an affected child, a one in two chance of a carrier and a one in four chance of a child who is neither affected nor a carrier.

Royal Brompton says there is currently no definitive test to determine who is a carrier, but some tests offer reasonable success. Genetic counselling through the NHS clinical genetics service can help families understand their options, including testing in later pregnancies.

PCD Support UK is the national charity for people with PCD and offers information for adults and children, details of the specialist centres and a family support network. Most children attend school and take part in activities, and the physiotherapist can advise on exercise as part of airway clearance.

Practical steps include keeping vaccinations up to date, treating colds and chest infections promptly, avoiding smoke, and having a plan with your team for what to do when your cough becomes more productive or a fever develops.

In the UK, PCD is diagnosed and managed through NHS specialist centres, with shared care between those centres and local respiratory or paediatric teams. A GP is the usual route to referral.

Private respiratory clinics may offer initial assessment and imaging, but confirmatory testing and long-term specialist care are concentrated in the national NHS centres, so many people use both a local and a specialist team.