Wilson-Mikity syndrome: updated diagnostic criteria based on nine cases and a review of the literature.

Background: Nearly 50 years ago, Wilson and Mikity described a syndrome (WMS) of chronic lung disease (CLD) in premature infants, characterized by early development of cystic interstitial emphysema (PIE), despite minimal ventilatory support. The validity of the diagnosis is currently unclear; now considered either an anachronism, part of BPD spectrum or included within various poorly defined diagnoses such as chronic pulmonary insufficiency of prematurity (CPIP).

Objectives: To define clinically useful diagnostic criteria for WMS so its position in the spectrum of CLD of infancy can be established.

Methods: We studied nine patients who fulfilled WMS criteria, combining this data with a detailed review of the available literature.

Results: Despite minimal respiratory support at birth, all developed generalized or lobar cystic PIE by 3 weeks of age, followed by slow inflammatory progression over a further 2-3 months. Final outcome was variable but most were left with some degree of CLD.

Conclusions: WMS is a rare but clearly identifiable syndrome with significant morbidity, predominantly affecting infants below 1,500 g birth weight. The earliest pathology appears to be alveolar air leak. Inflammatory activation induced by cystic interstitial air may cause the subsequent progressive respiratory disease. Management is supportive but should include investigation for pulmonary hypertension.