Interstitial lung disease in children — clinical case

Case summary

This infant presents with the defining picture of children's interstitial lung disease in infancy: months of persistent tachypnoea that never settled despite treatment for presumed bronchiolitis, diffuse fine crackles, hypoxaemia unmasked by feeding, and failure to thrive. The essential insight is that chronic, diffuse respiratory trouble of this kind is not a run of infections but an abnormal interstitium, and she meets the chILD syndrome — respiratory symptoms, respiratory signs, hypoxaemia, and diffuse imaging change — once the common causes have been excluded. [1] [2]

Initial assessment and investigations

The history and examination are directed at confirming that the process is chronic and diffuse, gauging its severity, and hunting for a cause. The tachypnoea has persisted for months, the crackles are diffuse rather than focal, and oximetry during feeding reveals the true extent of the hypoxaemia. A careful family history for neonatal deaths and consanguinity is taken because a genetic surfactant disorder is possible. [1] [4]

Because the chILD syndrome only applies once common causes are excluded, that work is done first: a sweat test and cystic fibrosis genetics are normal, an immune screen is unremarkable, a swallow assessment shows no aspiration, and an echocardiogram excludes congenital heart disease while showing no pulmonary hypertension. A high-resolution CT of the chest is then obtained and shows ground-glass opacity in the right middle lobe and lingula with mosaic air trapping — a pattern characteristic of neuroendocrine cell hyperplasia of infancy. A surfactant-gene panel is sent and returns negative. [4] [3]

Management

Because the HRCT pattern is classic and the surfactant genes are negative, a diagnosis of neuroendocrine cell hyperplasia of infancy is made without a lung biopsy, sparing her an invasive procedure and needless immunosuppression. Management is supportive: supplemental oxygen is started to correct the hypoxaemia and protect growth and the pulmonary circulation, nutrition is optimised with high-energy feeds and dietitian input, immunisations including influenza are completed, respiratory syncytial virus prophylaxis is arranged, and the home is made smoke-free. Corticosteroids are deliberately not used, because this condition does not respond to them and improves with time. [1] [3]

Disposition and counselling

She is placed in structured multidisciplinary follow-up at a specialist chILD centre, with monitoring of oxygenation, growth, and lung function and periodic assessment for pulmonary hypertension. The family is counselled that neuroendocrine cell hyperplasia of infancy, although it causes alarming persistent breathlessness, generally improves gradually over several years, that supplemental oxygen and good nutrition are the treatments that matter, and that the negative genetic panel is reassuring for future children. They are given a clear plan for when to seek help during intercurrent infections, which can transiently worsen her breathing. [4] [1]