Chronic Obstructive Pulmonary Disease (COPD) Exacerbation: Given the patient's age and symptoms of productive cough and wheezing, a COPD exacerbation is highly plausible. This condition is common in elderly patients, especially those with a history of smoking or exposure to lung irritants.

Asthma: Although more commonly diagnosed in younger populations, asthma can occur at any age. The presence of wheezing and cough could suggest asthma, particularly if the patient has allergies or other triggers.
Acute Bronchitis: This condition, often caused by a viral infection, can present with a productive cough and wheezing. It's a common cause of respiratory symptoms in the elderly.
Influenza or Other Viral Respiratory Infections: Given the symptoms of cough, wheezing, and sinus pressure, a viral respiratory infection such as influenza could be a likely diagnosis, especially during flu season.
Pneumonia: While the question asks if the patient should be treated for pneumonia, it is indeed a possible diagnosis, especially if the patient has a fever, increased sputum production, or other signs of infection. However, the presence of sinus pressure and wheezing might suggest other diagnoses initially.

Pulmonary Embolism: Although less likely given the symptoms, pulmonary embolism is a potentially life-threatening condition that must be considered, especially in elderly patients with risk factors such as immobility, cancer, or recent surgery.
Cardiac Failure: Congestive heart failure can present with cough and wheezing due to pulmonary edema. This diagnosis is critical not to miss, as it requires specific treatment.
Lung Cancer: In an elderly patient with new onset of respiratory symptoms, lung cancer must be considered, especially if there's a history of smoking.

Cystic Fibrosis: Although extremely rare in an 83-year-old, if the patient has had recurrent respiratory infections or other suggestive symptoms throughout life, cystic fibrosis could be considered.
Bronchiectasis: This condition, characterized by permanent dilation of parts of the airways, can cause chronic cough and sputum production. It's less common but could be a consideration in patients with recurrent infections or specific risk factors.
Allergic Bronchopulmonary Aspergillosis (ABPA): This rare condition occurs in people with asthma or cystic fibrosis and is caused by an allergic reaction to a fungus. It could present with worsening respiratory symptoms but is less likely in this age group without a known history of asthma or cystic fibrosis.