Snapshot A 3-year-old boy with growth retardation has a long history of recurrent pneumonia and chronic diarrhea. His mother states that he has 6-8 four smelling stools per day. PE reveals a low grade fever, scattered rhonchi over both lung fields, crepitant rales at the left lung base and dullness to percussion. Other findings include mild hepatomegaly and slight pitting edema of the lower extremities. His HgB is 7.5, and WBC shows 18K with a neutrophillic leukocytosis and 15% bands. Introduction Cystic fibrosis is a genetic disorder leading to excessive, viscous secretions that plug exocrine glands autosomal recessive disorder caused by mutations in CFTR gene (chloride channel) on chromosome 7 Affects multiple organ systems with widespread exocrine gland dysfunction pancreatic exocrine insufficiency is responsible for most of them Epidemiology most common, lethal genetic disease in the United States mostly affects Caucasians some states perform routine prenatal screening Presentation Symptoms respiratory symptoms are more prominent in adulthood recurrent pulmonary infections Pseudomonal spp are more common in S. aureus is more common in pediatric patients chronic sinusitis chronic, productive cough dyspnea on exertion bronchiectasis hemoptysis gastrointestinal symptoms are more prominent in infancy chronic, frequent diarrhea greasy stool with flatulence from malabsorption secondary to pancreatic insufficiency can lead to rectal prolapse meconium ileus in infants (15%) Physical exam failure to thrive (50%) respiratory compromise (50%) "salty taste" cyanosis digital clubbing ronchi rales hyperresonane to percussion nasal polyposis infants present with meconium ileus (15%) calcium oxalate kidney stones idiopathic hyponatremia glucose intolerance, Type II diabetes pancreatis fat-soluble vitamin deficiency (low vitamin A, D, K, and E) esophageal varices bilial cirrhosis infertility (95%) Evaluation Sweat chloride test historical diagnostic gold standard >60 mEq/L in patients <20 years old >80 mEq/L in adults Genetic testing confirms disease by identification of specific genetic mutation Immunoreactive trypsinogen assay Differential Recurrent pneumonia, bronchiectasis, interstitial lung disease Treatment Non-operative respiratory therapy indicated periodically in all patients usually requires hospitalization or visiting nursing care providing includes several components including chest physical therapy bronchodilators corticosteriods DNA-ase antibiotics anti-inflammatory agents pancreatic enzymes and fat-soluble vitamins indicated for malabsorption health maintenance nutritional counseling psychiatric/psychologic support indicated in most patients with or without mental instability up-to-date immunizations indicated in all patients Operative lung and pancreas transplantation indicated for most severe, but only if patient can tolerate surgery Prognosis, Prevention, and Complications Prognosis while patients are living longer and more complete lives with modern medicine, rarely do CF patients live beyond 40 years of age without transplantation Prevention immunization for influenza and pneumococcus can prevent infections embryonic selection, although controversial, has been used by known carriers or affected couples to prevent transmission of the disease to their children Complications patients often develop cor pulmonale (RHF) patients usually succomb to recurrent, drug-resistent bacterial or fungal pneumonias