Cystic Fibrosis Clinical Presentation

Updated: Sep 08, 2022
  • Author: Girish D Sharma, MD, FCCP, FAAP; Chief Editor: Kenan Haver, MD  more...
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Median age at diagnosis of cystic fibrosis is 6-8 months; two thirds of patients are diagnosed by 1 year of age. The age at diagnosis varies widely, however, as do the clinical presentation, severity of symptoms, and rate of disease progression in the organs involved. Clinical manifestations vary with the patient's age at presentation.

Neonates may present with meconium ileus or, rarely, with other features such as anasarca. Patients younger than 1 year may present with wheezing, coughing, and/or recurring respiratory infections and pneumonia. GI tract presentation in early infancy may be in the form of steatorrhea, failure to thrive, or both.

Patients diagnosed later in childhood or in adulthood are more likely to have pancreatic sufficiency and often present with chronic cough and sputum production. Approximately 10% of patients with cystic fibrosis remain pancreatic sufficient; these patients tend to have a milder course.

Gastrointestinal tract manifestations

Meconium ileus occurs in 7-10% of patients with cystic fibrosis. Patients with simple meconium ileus usually present with abdominal distension at birth, eventually progressing to failure to pass meconium, bilious vomiting, and progressive abdominal distension.

Patients with complicated meconium ileus present more dramatically at birth with severe abdominal distention, sometimes accompanied by abdominal wall erythema and edema. Abdominal distention may be severe enough to cause respiratory distress.

Other GI manifestations in neonates include intestinal obstruction at birth and various surgical findings (eg, volvulus, intestinal atresia, perforation, meconium peritonitis). Less commonly, passage of meconium may be delayed (>24-48 hours after birth) or cholestatic jaundice may be prolonged.

Infants and children present with increased frequency of stools, which suggests malabsorption (ie, fat or oil drops in stools), failure to thrive, intussusception (ileocecal), or rectal prolapse.

Patients with pancreatic insufficiency have fat-soluble vitamin deficiency and malabsorption of fats, proteins, and carbohydrates (however, malabsorption of carbohydrates is not as severe as that of fats and proteins). Patients present with failure to thrive (despite an adequate appetite), flatulence or foul-smelling flatus, recurrent abdominal pain, and abdominal distention.

Malabsorption results in steatorrhea, characterized by frequent, poorly formed, large, bulky, foul-smelling, greasy stools that float in water. Cloth diapers, if used, are difficult to clean. Alternatively, some patients have anorexia without obvious steatorrhea.

Patients may present with a history of jaundice or gastrointestinal tract bleeding as a result of hepatobiliary involvement.

Respiratory tract manifestations

Patients present with a chronic or recurrent cough, which can be dry and hacking at the beginning and can produce mucoid (early) and purulent (later) sputum. Prolonged symptoms of bronchiolitis occur in infants. Paroxysmal cough followed by vomiting may occur.

Recurrent wheezing, recurrent pneumonia, atypical asthma, pneumothorax, hemoptysis, and digital clubbing are all complications and may be the initial manifestation. Dyspnea on exertion, history of chest pain, recurrent sinusitis, nasal polyps, and hemoptysis may also occur.

Urogenital tract manifestations

Undescended testicles or hydrocele may be present in boys. Males are frequently sterile because of the absence of the vas deferens. Therefore, male infertility may be one of the presentations.

Fertility is maintained, although possibly decreased, in females. Secondary sexual development is often delayed. Amenorrhea may occur in females with severe nutritional or pulmonary involvement.


Physical Examination

Physical signs depend on the degree of involvement of various organs and the progression of disease.

Nose examination may reveal the following:

  • Rhinitis

  • Nasal polyps

Findings related to the pulmonary system may include the following:

  • Tachypnea

  • Respiratory distress with retractions

  • Wheeze or crackles

  • Cough (dry or productive of mucoid or purulent sputum)

  • Increased anteroposterior diameter of chest

  • Clubbing

  • Cyanosis

  • Hyperresonant chest upon percussion (crackles are heard acutely in associated pneumonitis or bronchitis and chronically with bronchiectasis)

Findings related to the GI tract include the following:

  • Abdominal distention

  • Hepatosplenomegaly (fatty liver and portal hypertension)

  • Rectal prolapse

  • Dry skin (vitamin A deficiency)

  • Cheilosis (vitamin B complex deficiency)

Examination of other systems may reveal the following:

  • Scoliosis

  • Kyphosis

  • Swelling of submandibular gland or parotid gland

  • Aquagenic wrinkling of the palms (AWP)

One study reported an association between AWP and cystic fibrosis. [26] Among patients with cystic fibrosis, a greater degree of AWP is observed in patients who are homozygous for the ΔF508 mutation.

A study by Kelly et al sought to characterize cortical and trabecular volumetric bone mineral density (vBMD), geometry, and biomechanical competence in children with CF and determine their relationship to growth, body composition, and disease severity. The study found that trabecular and cortical bone deficits are common in children and adolescents with cystic fibrosis and that females are at particular risk of poor bone health. [27, 28]

Meconium ileus

Often, examination reveals dilated loops of bowel with a doughy character that indent on palpation. The rectum and anus are usually narrow, a finding possibly misinterpreted as anal stenosis.

Signs of peritonitis include tenderness, abdominal wall edema, distention, and clinical evidence of sepsis. A palpable mass may indicate pseudocyst formation. Often, the neonate is in extremis and needs urgent resuscitation and surgical exploration.

Atypical manifestations

Clinical variants have been described, such as adult males with bilateral absence of the vas deferens who have little other clinical involvement. Absence of the vas deferens is considered an atypical presentation of cystic fibrosis, and 80% of men with this presentation have at least one CFTR gene mutation. Zielenski et al reported that the most common of these mutations is the IVS8/5T mutation. [29]

Another atypical manifestation of cystic fibrosis is polyuria and polyphagia in an infant. Despite not having any initial intestinal symptoms, such as diarrhea, an infant in Belgium with failure to thrive was initially treated for diabetes insipidus before being diagnosed with cystic fibrosis. [30] Although a sweat test result may be abnormal in diabetes insipidus, cystic fibrosis must be excluded upon any positive sweat test result.


The following are potential complications of cystic fibrosis:

  • Nasal polyps

  • Chronic and persistent sinusitis with complications such as mucopyocele formation

  • Bronchiectasis

  • Atelectasis

  • Pneumothorax

  • Hemoptysis

  • Hypertrophic pulmonary osteoarthropathy

  • Allergic bronchopulmonary aspergillosis (ABPA)

  • Gastroesophageal reflux

  • Pulmonary hypertension

  • Cor pulmonale

  • End-stage lung disease

  • Pancreatitis

  • Cystic fibrosis–related diabetes mellitus

  • Meconium ileus

  • Distal intestinal obstruction syndrome

  • Rectal prolapse

  • Vitamin deficiency (especially fat-soluble vitamins)

  • Fatty liver

  • Focal biliary cirrhosis

  • Portal hypertension

  • Liver failure

  • Cholecystitis and cholelithiasis

  • Rickets

  • Osteoporosis