Differential Diagnosis for Sinusitis
The differential diagnosis for sinusitis over the last three weeks can be categorized as follows:
- Single Most Likely Diagnosis
- Viral Sinusitis: This is the most common cause of sinusitis, often following an upper respiratory tract infection. The symptoms typically resolve within 7-10 days, but some cases can persist for up to three weeks.
- Other Likely Diagnoses
- Bacterial Sinusitis: This can occur as a secondary infection following viral sinusitis, especially if symptoms worsen or persist beyond 7-10 days. Common bacteria include Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.
- Allergic Rhinitis: This condition can cause chronic sinusitis symptoms, especially in patients with allergies. The symptoms can be similar to those of infectious sinusitis, including nasal congestion, discharge, and facial pressure.
- Chronic Sinusitis: This condition is defined as sinusitis lasting more than 12 weeks, but some cases can have a subacute presentation lasting several weeks.
- Do Not Miss Diagnoses
- Invasive Fungal Sinusitis: Although rare, this condition can be life-threatening, especially in immunocompromised patients. It requires prompt diagnosis and treatment.
- Tuberculous Sinusitis: This is a rare cause of sinusitis, but it can be deadly if missed. It often presents with chronic symptoms and can be associated with other systemic symptoms.
- Wegener's Granulomatosis (Granulomatosis with Polyangiitis): This is a rare autoimmune disorder that can cause sinusitis, as well as other systemic symptoms. It requires prompt diagnosis and treatment to prevent serious complications.
- Rare Diagnoses
- Sarcoidosis: This is a rare autoimmune disorder that can cause sinusitis, as well as other systemic symptoms. It often presents with chronic symptoms and can be associated with other organ involvement.
- Eosinophilic Mucin Rhinosinusitis: This is a rare condition characterized by the presence of eosinophilic mucin in the sinuses, often associated with asthma and other allergic conditions.
- Sinusitis due to Uncommon Bacteria: Such as actinomycosis or nocardiosis, which can occur in specific contexts, like immunocompromised states or after trauma.