A parent comments that her infant has had several ear infections in the past few months. Why are infants more susceptible to otitis media?

A. Rheumatic fever often develops as a complication of untreated or inadequately treated streptococcal throat infections, particularly group A Streptococcus. A history of a recent sore throat in a family member could suggest a streptococcal infection, which is a risk factor for developing rheumatic fever.

B. Chickenpox is caused by the varicella-zoster virus and is not directly related to rheumatic fever. While viral infections can trigger or exacerbate rheumatic fever in susceptible individuals, chickenpox itself is not a significant risk factor for rheumatic fever.

C. Fifth disease, also known as erythema infectiosum, is caused by parvovirus B19 and is not associated with rheumatic fever. Fifth disease primarily affects the skin, causing a characteristic rash, and is typically a mild illness in children.

D. Gastritis, inflammation of the stomach lining, is not directly related to rheumatic fever. While some gastrointestinal conditions may be associated with autoimmune disorders, gastritis itself is not a known risk factor for rheumatic fever.

A. Wheezing. Cystic fibrosis can cause airway obstruction due to thickened mucus, leading to wheezing and difficulty breathing, especially during respiratory infections or exacerbations.

B. A barrel-shaped chest is often seen in advanced stages of cystic fibrosis. It results from hyperinflation of the lungs due to air trapping, chronic lung disease, and repeated respiratory infections. The chest appears rounded and enlarged, similar to the shape of a barrel.

D. Clubbing of fingers and toes is a common finding in cystic fibrosis. It is caused by chronic hypoxia and inadequate oxygenation of tissues, leading to changes in the nail beds and fingertips. Clubbing typically develops over time in individuals with chronic respiratory conditions, including cystic fibrosis.

C. Thin, watery mucous is not expected in cystic fibrosis. Instead, cystic fibrosis is characterized by thick, sticky mucus due to dysfunction of the exocrine glands, leading to blockages in the airways, pancreas, and other organs.

E. Rapid growth spurts are not typically associated with cystic fibrosis. In fact, children with cystic fibrosis may experience growth failure or delayed growth due to malabsorption of nutrients, chronic illness, and increased energy expenditure.