Differential Diagnosis between Bacterial and Viral Infection of the Throat

Patient Scenario Paper to include:

• Answers to all six questions including all sub-parts of each question. Provide some details in your answer. It should take no more than three (3) pages to provide answers to all the questions, number each page. Number the response to each question in your write-up.
• Your grade will depend upon the content, clarity and originality of responses written in your own words.
• Cite all sources in APA format at the end of the short paper.

Addresses Learning Outcomes:

• Use knowledge of biological principles and the Scientific Method to ask and answer relevant questions about human health and disease
• Analyze information to distinguish between diseased and healthy structure and functioning.
• Analyze how internal and external factors cause disruption of healthy body function, leading to disease and disorders.

Mr. Smith is 60 years old. He was diagnosed with a prostate cancer five years ago. Over the past few days, Mr. Smith has been feeling weak and increasingly tired and has also been suffering from a headache that did not respond to over-the-counter medications. He scheduled an appointment with his physician.

His physician performed a physical examination and recommended a battery of laboratory tests and imaging procedures.

The table below shows Reference values in the right-hand column. These values reflect the normal range of values for patients without disease or illness.  The center column reflects the resulting values for medical test results obtained for Mr. Smith.

 Take note whether Mr. Smith’s values are within normal limits.

Mr. Smith

Reference Values

K+

2.6 mmol/L 

3.8-4.9mmol/L

Hb (Hemoglobin)

7.5 g/dL  

13.8 to 18.2 g/dL

Hct (Hematocrit)

20.4%      

45-52%

Platelet Count

49×109/L

150-400×109/L

After receiving Mr. Smith’s test results, his physician admits him to the hospital. Hospital staff treated him and discharged him.

The following week, Mr. Smith returns to his physician with the same complaint of weakness and a new complaint of shortness of breath. His blood pressure is 160/100 mmHg.  MRI reveals metastasis of prostate cancer to osseous tissue. Abdominal CT shows obstruction of intestine due to nodular enlargement of adrenal glands.

Laboratory results from Mr. Smith’s second hospital admission and medical tests show following findings:

Mr. Smith

Reference Values

K+

2.6 mmol/L

3.8-4.9mmol/L

Hb

7.3 g/dl

13.8 to 18.2 g/dL

Hct

20.4%

45-52%

Platelet Count

20×109/L 

150-400×109/L

HCO3

38 mmol/l

22-26 mmol/L

Urinary K+

70 mmol/L/24 hr

25-120 mmol/L/24 hr

Blood Glucose

460 mg/dl

64.8-104.4 mg/dL

Serum Aldosterone

1 ng/dl

24 hour Urinary Aldosterone

8.4 mcg/24 hr

2.3-21.0 mcg/24 hr

Renin

2.1 ng/ml/hr

0.65-5.0 ng/ml/hr

ACTH (Adrenocorticotropic Hormone)

1082 pg/ml

9-46 pg/ml

Cortisol

155.5 microg/dL

0-25 microg/dL

CONCLUSION AND DIAGNOSIS 

Laboratory findings, MRI and CT confirmed metastatic prostate adenocarcinoma, hypertension and refractory hypokalemia due to ectopic ACTH production. High levels of circulating cortisol caused continuous activation of mineralocorticoid receptors resulting in hypokalemia, metabolic alkalosis and hypertension.

After reading provided scenario, answer the following questions:

1.   What are the components of physical examination? Describe each component. (See Module 1, Commentary, Topic 8. Disease Categories, Part B. Steps in Diagnosis)

Reading Module 1, Commentary, Topic 8. Disease Categories, Part B. Steps in Diagnosis

1. Taking a History of the Disease

The first step in determining a correct diagnosis is collecting the history of the symptoms starting from the most recent. Patients should have an opportunity to tell their own story. However, the physician should listen carefully and elicit all relevant information pertaining to the symptoms such as the onset, duration, and possible relief. The physician should ask appropriate questions, not only about the patient’s medical history, but also about family, social, and work history because some disorders tend to run in families or are related to social behaviors or workplace conditions.

Physical Examination

After listening to the patient’s description of the history of the symptoms, physicians generally conduct a physical examination, which includes:

• Observing the physical signs of a disease and evaluating, for example, posture, facial expression, mobility, alertness, responsiveness to stimuli, changes in skin color.
• Taking the patient’s vital signs, including blood pressure, heart rate, and breathing rate, along with temperature and comparing them to the reference ranges.
• Using a stethoscope in a procedure called auscultation to listen to the lungs, heart, and bowel movement. A healthy heartbeat sounds different than a heartbeat of a heart with valve damage.
• Tapping on the chest and abdomen in a procedure called percussion produces a specific sound under normal conditions. If there is fluid or excess air in the lungs, this sound will change. By tapping along orientation lines, a physician can determine the size of the lungs and the size of the area affected by a disease. (This procedure may not be used very often.)
• Using the fingers and applying pressure in a procedure called palpation to feel the body regions and the organs within them. Palpation provides information about the size of an organ and changes in its consistency, shape, and tenderness, and can help determine the presence of a foreign mass.

The results of the physical examination allow the physician to limit the number of possible causes of the patient’s disorder and order appropriate laboratory and imaging tests.

Investigative Tests and Procedures

Laboratory tests, ultrasound, imaging procedures, nuclear scans, and clinical procedures play important roles in differential diagnosis (a process of distinguishing between diseases with similar signs and symptoms)—that is, they allow the doctor to narrow the diagnoses (see Table 1.7).

Table 1.7
Examples of Tests and Procedures

Tests and ProceduresExamples

Laboratory tests

Complete blood count, concentration of electrolytes in blood, amount of cholesterol in plasma, glucose tolerance test, skin tests, urinalysis

Imaging techniques

Ultrasound, magnetic resonance imaging (MRI), computer tomography (CT), X-rays

Nuclear scans

Positron emission tomography (PET), thyroid scan, bone scan

Clinical procedures

Biopsy, electrocardiogram (ECG), electroencephalogram (EEG), Pap smear, endoscopy, colonoscopy

Simplified Differential Diagnosis of a Sore Throat

A sore throat is a common complaint and is most commonly caused by the viruses responsible for the common cold. Another frequent cause is a bacterial infection. According to Principles of Internal Medicine, about 15 percent of bacterial infections are caused by group A Streptococcus pyogenes (Braumwald, 2001, p. 191). Ways of determining whether a sore throat is caused by a bacterial infection or by a viral infection are shown in Table 1.8 below.

You may wonder why it is important to differentiate between viral and bacterial infections. First of all, the treatment for bacterial infections differs from the treatment for viral infections. Antibiotics are effective only for bacterial infections. Second, if the sore throat is caused by group A streptococci, an untreated infection may lead to severe complications including abscesses at the site of the infections (tonsils and throat) and rheumatic fever.

Differential Diagnosis between Bacterial and
Viral Infection of the Throat

Etiology: Bacterial (streptococci, Groups A, C, and G)Etiology: Viral (rhinovirus, coronavirus, parainfluenza virus)

History

Possible exposure in social or work setting

Symptoms: sore throat, painful swallowing, tiredness, fever, and muscle ache

Possible exposure in social or work setting

Symptoms: sore throat, painful swallowing, tiredness, fever, sneezing, difficulty breathing through the nose

Vital signs

Vitals within norm, possible high-grade fever

Vitals within norm, possible low-grade fever

Inspection and signs

• Red throat
• Swollen tonsils
• Swollen uvula
• White spots on tonsils
• Grayish tongue
• Red throat
• Swollen tonsils

Auscultation

Heart, lungs normal

Heart, lungs normal

Percussion

Lungs, abdomen normal

Lungs, abdomen normal

Palpation

Enlarged tonsils, lymph nodes

Enlarged tonsils

Laboratory test—culture

Positive for presence of streptococci

Negative for presence of streptococci

Figure 1.9 displays the most common differences between sore throats caused by viral infections and sore throats caused by bacterial infections.

Figure 1.9
Differences between Bacterial and Viral Infection

2.   Mr. Smith’s blood pressure was 160/100 mmHg. How does a medical provider take or measure blood pressure? What do the top (numerator) and bottom (denominator) numbers mean in the biological sense? What is the significance the size of these two numbers? Is Mr. Smith’s blood pressure within normal range? Explain how you concluded whether Mr. Smith’s blood pressure is/is not within normal range.

3.   Based on the data provided, what laboratory tests were performed and what samples were taken from the patient?  Select one of the laboratory tests ordered for Mr. Smith and discuss why Mr. Smith’s physician might have ordered the test and the information she might have expected to obtain from that particular test.

4.   Compare Mr. Smith’s values with reference values and indicate whether MR. Smith’s values are below, above, or within normal range (compare Mr. Smith’s values with the Reference values) for each laboratory tests in the table above from the second set of tests. 

5.   What imaging procedures did Mr. Smith undergo? Discuss the distinctions and similarities between the two different imaging approaches. What were the results of imaging procedures in Mr. Smith’s case?

6. Select one of the medical terms from the CONCLUSION and DIAGNOSIS section above and define what it means.  Also, discuss, in your own words and based on what you can gather about Mr. Smith’s condition, how the laboratory or imaging tests helped with drawing a conclusion or making the diagnosis. In your own words, discuss how medical providers use the scientific method to come to work through the examination and diagnosis of a patient.

You should write a short paper addressing all six questions and submit it into the assignment folder. Your grade will depend upon the content, clarity and originality of responses written in your own words. Good writing practices, including the use of correct grammar, sentence and paragraph structure, and punctuation, and presence of logical reasoning, will account for a portion of your grade.

Cite all sources in APA format within your answer text as well as full citations in APA format at the end of the assignment.