Given a presumptive diagnosis of influenza and a positive flu swab you initiated oseltamivir 75 mg PO bid x 5 days. She slowly improves over the next 5 days but then relapses and returns with a fever, fatigue, cough and mild dyspnea a little over a week following the last appointment. She is not aching nor does she have other complaints. What is your differential diagnoses now and your next diagnostic steps?

Krista E. is a 41-year-old female seen in the office with fever, shaking, chills, coughing, increasing SOB, and increasing fatigue. Symptoms began 24 hours ago. The region in which you are practicing is experiencing peak flu season. This patient did not receive influenza vaccination.

What is your presumptive diagnosis and differential diagnoses? What therapeutic options exist? What medications and doses are appropriate for this patient?

Krista a 41 year old patient in a doctor's office with a fever, shaking, chills, coughing, increasing SOB and increasing fatigue. Krista temperature is 103.5, BP 145/76, and she is a smoker. The presumptive diagnosis is Influenza, which is a serious disease that can lead to hospital admission and sometimes can even lead to death if not appropriately treated. The disease can affect people differently. Even healthy individuals can get influenza and spread it to others. Some of the symptoms for Influenza include; high fever, coughing or a sore throat, a runny nose, chills, headaches, fatigue, body aches, nausea among others. (Urashima et al, 2010).

Differential Diagnosis in order of presumption;

• Pneumonia - possibly a development of the influenza. The pneumonia may be suggested by the     rales, increasing shortness of breath

• Acute or Chronic Bronchitis - to diagnose her with bronchitis we would need to find out more regarding her symptoms, her cough particularly, if it is productive, a more thorough physical as well would be in place.

• Common Cold - though not really likely due to all the other symptoms she is experiencing

The most common testing method for influenza is a rapid diagnostic test. This test typically takes about thirty minutes or less and can provide the physician with a positive or negative result. The reliability of the rapid tests does vary widely based on the conditions under which they are used. Sensitivities of the rapid influenza diagnostic tests are approximately 50-70%, and specificities of the rapid diagnostic tests for influenza are approximately 90-95%, when they are compared with viral culture or reverse transcription polymerase chain reaction (RT-PCR). Using a rapid test with high sensitivity and specifity will minimize the false results. It is important to take a respiratory specimen early on in the illness and send it for a RT-PCR to confirm the results of the rapid test ("Treatment - Antiviral Drugs", 2015). If a patient has, respiratory symptoms such as dyspnea and rales noted during the physical examination a pulse oximetry to detect hypoxemia and a chest x-ray to detect pneumonia should be done.

Krista should be encouraged to avoid any close contact with other people and those that are sick as she can put them at risk for developing the flu. She should be told to wash her hands often, and avoid touching eyes, nose, and mouth. If she does need to be near people she should wear a face mask if possible, if not she should at least cover her coughs and sneezes with a tissue. The CDC recommends taking the H1N1 influenzas (Flu) shot during the flu season. She should stay home till 24 hours after she has not had any fever.

Medication;

The medication and dose recommended for the patient is the use of Oseltamivir (Tamiflu) for treatment. 75mg of Oseltamivir should be taken orally twice a day for five days to treat Influenza (Urashima et al, 2010).  Tamiflu is an antiviral drug that treats those who have not had the flu symptoms for more than two days. Since our patient has had symptoms for 24 hours she can take the Tamiflu. The antiviral medications are approximately 70% to 90% effective in preventing influenza as the adjuncts to the vaccination as well.

There are not many side effects to the Tamiflu. Most commonly there may be nausea and vomiting which usually will not be severe and will happen in the first two days of the treatment. If the Tamiflu is taken with food, it may decrease the chances of these effects. Other side effects may be abdominal pain, nosebleeds, headache, and fatigue ("Tamiflu", 2014).

In addition to taking care of the flu, I would want to counsel her regarding the important of the flu vaccination as well as smoking cessation. It is possible that her smoking is contributing to her cough and even if it currently is not, it is definitely not something that yields positive results in any case. Additionally some of her lab values though they are not alarmingly out of range are low. I would want to keep an eye on that as well, and follow up on it with her when she is feeling better.

References;

Tamiflu (oseltamivir phosphate) Information. (2014). Retrieved November 18, 2015, from http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm107838.htm

Treatment - Antiviral Drugs. (2015, September 16). Retrieved November 18, 2015, from http://www.cdc.gov/flu/antivirals/index.htm

Urashima, M., Segawa, T., Okazaki, M., Kurihara, M., Wada, Y., & Ida, H. (2010). Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren. The American journal of clinical nutrition, 91(5), 1255-1260.