Inflammation and infection of the frontal sinus - frontal sinusitis, is distinguished by the presence of symptoms such as a headache and pain in the superior part of the orbits, in addition to rhinorrhea, discharge, and nasal obstruction. Frontal sinusitis poses the greatest risk for intracranial complications, which is why an early diagnosis is a must. A thorough clinical workup supported by imaging studies is sufficient to make the diagnosis.
Sinusitis is considered to be a rather common entity in clinical practice, as studies show that up to 31 million diagnoses are made in the United States alone each year [1] [2]. Sinusitis may be classified according to the duration of symptoms (acute, subacute, chronic, or recurrent) and the etiology (bacterial, viral, or fungal) [1] [3] [4]. If symptoms last up to 4 weeks (or 30 days by some authors), the term acute sinusitis is used; when four or more episodes of acute sinusitis are seen during the year, the diagnosis of recurrent sinusitis can be made; and conversely, chronic sinusitis develops when symptoms last more than 90 days (or 12 weeks) [1] [3] [4] [5]. The clinical presentation of sinusitis (regardless of the exact sinus involved) is comprised of symptoms such as nasal obstruction, discharge, localized pain, and headaches [4] [5] [6] [7]. Some studies show that vomiting may be a common symptom as well [7]. However, the frontal sinusitis is suspected when a headache, described as constant and dull pain, is localized to the forehead or the superior aspects of the orbit [1] [4] [8]. Frontal sinusitis is known for causing intracranial complications, primarily because of its anatomical proximity to the meninges and the venous sinuses [1] [8] [9]. For this reason, an early diagnosis is mandatory.
The workup of frontal sinusitis should start with a complete patient history that will include the duration of symptoms and their progression [1]. A presumptive diagnosis in terms of etiology can be made based on the duration of complaints, as viral sinusitis (rhinovirus, influenza virus and parainfluenza virus) is more likely when the illness lasts < 10 days, whereas bacterial pathogens (staphylococcus aureus, streptococcus pneumoniae, haemophilus influenzae, moraxella catarrhalis, etc.) should be considered with a prolonged clinical course [1] [6]. A thorough physical examination, comprised of cranial inspection, palpation of the sinuses (which reveals tenderness in the frontal area in the case of frontal sinusitis), and anterior rhinoscopy must follow in order to obtain sufficient evidence to make the diagnosis [1]. Imaging studies are recommended for solidifying clinical suspicion and plain radiography is the first-line study for sinusitis [1] [5]. The frontal view (known as Caldwell‐Luc view) is used to assess the frontal sinuses and can reveal opacification of the sinus or the presence of an air-fluid level [3] [5]. Computed tomography (CT), however, is a superior method that is able to provide a better view into the sinuses and their anatomical landmarks, which is why it is favored over X-rays [1] [3] [5]. In some patients, puncture of the frontal sinus might be indicated to obtain viable material for microbiological investigation, especially if fungal pathogens are suspected [3] [5].