Lung involvement in multi-system disease is rare in children. When it does occur it is associated with significant morbidity and mortality. Auto-immune diseases such as systemic lupus erythematosis, scleroderma and acute rheumatic disease can cause major lung pathology. Chronic illness such as sickle cell disease, mucopolysaccharidosis or familial dysautonomia can result in long-term recurrent respiratory problems. Rare conditions such as sarcoidosis, pulmonary lymphangiomatosis or Langerhan's histiocytosis occasionally result in major lung disease in this age group. The prognosis for all of these conditions is very variable depending on the severity of the disease itself and its response to treatment which often involves the use of oral corticosteroids or other powerful immuno-suppressants.