The use of flexible or rigid nasal endoscopy in children can be helpful in the diagnosis of sinusitis and the exclusion of nasal foreign bodies or polyposis as a potential cause of sinusitis. The benefits of this invasive examination must be weighed against the possible risks given the age and cooperativeness of the pediatric patient.

Plain films have little diagnostic value for evaluation of rhinosinusitis and should not be routinely used. Computed tomography (CT) with contrast or magnetic resonance imaging (MRI) with contrast in children should be considered for signs of acute complicated rhinosinusitis. Concern for orbital extension with proptosis, reduced or painful eye movement (ophthalmoplegia), decreased visual acuity (initially manifesting itself with reduced green/red color discrimination), or lethargy should prompt an urgent CT scan with contrast. MRI may be used when concerns of intracranial extension of disease are present, such as with intracranial cerebritis, abscess, or cavernous sinus thrombosis.

An additional update in AAP 2013 is that there is no indication for imaging for uncomplicated acute bacterial sinusitis. The basis of this recommendation is that there can be abnormalities seen on imaging studies in normal healthy children such as mucosal thickening or sinus opacification that could falsely lead to the diagnosis of acute bacterial sinusitis [16].

Children with chronic rhinosinusitis should be judiciously tested for contributing underlying conditions such as asthma, cystic fibrosis, and immunodeficiency.

The recommendations for treatment will vary depending on the time course and severity of the symptoms as discussed previously. According to EPOS, there is evidence that antibiotics and topical steroids are useful in the treatment of rhinosinusitis; the selection of monotherapy or combination therapy is based on the presumptive diagnosis and the severity of the disease.

The presumptive diagnosis of viral upper respiratory infection is made if symptoms have been present for 5 days or are remitting at that time, for which purely symptomatic treatment with nasal saline and decongestants is recommended. If symptoms have persisted for 10 days or are worsening after 5 days, the working diagnosis is post-viral sinusitis or acute bacterial rhinosinusitis. Based on the severity of symptoms, the recommendation is to initiate only topical nasal steroids for moderate symptoms and both topical steroids with antibiotics for severe symptoms. If patient improves after 48 h, the recommendation is to complete a treatment course of 7–14 days. If a patient fails to improve despite initial medical management, the recommendation is referral to an otolaryngologist (see Fig. 9.1).

The recommendations for antibiotics are based on studies where a clinical diagnosis of acute bacterial rhinosinusitis was made according to the criteria previously discussed. One recent randomized, placebo-controlled trial evaluated the efficacy of amoxicillin (90 mg/kg) with potassium clavulanate (6.4 mg/kg) or placebo in children 1–10 years of age with a clinical presentation compatible with bacterial ARS (persistent symptoms, acutely worsening symptoms, or severe symptoms) [17]. Symptom scores were obtained at multiple time points, and the children were evaluated at day 14 from onset of treatment and their condition rated as cured, improved, or failed. Twenty-eight patients in each group completed the study, and their average age was around 5 years. Children receiving the antibiotic were more likely to be cured (50 % vs. 14 %, p = 0.01) and less likely to experience treatment failure (14 % vs. 68 %, p < 0.001) than children receiving placebo.

The most significant areas of change from the 2001 guidelines are the addition of a clinical presentation designated as “worsening course,” inclusion of new data on the effectiveness of antibiotics in children with acute sinusitis, and a review of evidence indicating that imaging is not necessary to identify those children who will benefit from antimicrobial therapy [4].

Antibiotic therapy is indicated in acute sinusitis when symptoms are severe or persistent or if a child appears toxic. The guidelines suggest treatment for 10–14 days or for 1 week beyond symptom resolution.

For patients with chronic sinusitis, the guidelines indicate a prolonged 4-week treatment with a broad-spectrum beta-lactamase-resistant second-line antibiotic. If there is no clinical response after 1 week of treatment, changing the antibiotic should be considered. Cultures may also be considered at the time of initiation to direct therapy.

The guidelines make no recommendations on adjuvant treatments including saline irrigation, nasal steroids, decongestants, and mucolytic therapy citing inadequate evidence. Smaller studies have demonstrated saline sinus irrigation with efficacy in the treatment of acute and chronic sinusitis. The authors propose irrigation increases mucociliary flow, vasoconstriction, mechanically clears secretions, decreases bacterial counts, and clears allergens and environmental irritants from the nose [18, 19]. Cochrane reviews published on the use of saline irrigation in acute sinusitis in adults in 2010 and concluded that the trials were too small or too biased to be confident on benefits [20]. Intranasal steroids compared to placebo in children were shown to have modest reduction in symptoms although there are criticisms of the methodology for these studies [21]. There are several studies in acute sinusitis in adults which provide data supporting the use of intranasal steroid as either monotherapy or adjuvant therapy to antibiotics [22].

The AAP Subcommittee of Sinusitis and Committee on Quality Improvement recommended amoxicillin as first-line therapy for children younger than 2 years of age suspected of having acute bacterial sinusitis of mild to moderate severity who do not attend daycare and who have not been treated recently with an antimicrobial agent. They recommend an amoxicillin dose of either 45 mg/kg/day in two divided doses or 90 mg/kg/day in two divided doses. The AAP committees further recommended that children who did not improve while receiving the lower amoxicillin dose, children with more severe illness, and children who attend daycare should be treated with high-dose amoxicillin-clavulanate 80–90 mg/kg/day of amoxicillin component in two divided doses [23].

Allergic inflammation leads to nasal congestion and swelling of the mucous membrane, which may obstruct or impede normal sinus drainage. Subsequent inflammatory responses in the epithelium lead to an influx of granulocytes, with swelling and pain from the mucosa and thickened secretions. In children evidence of allergic rhinitis has been found in 36–60 % of patients with chronic rhinosinusitis [29–31].

Symptoms that can be associated with allergic rhinitis include sneezing, itching (of nose, eyes, ears, palate), rhinorrhea, postnasal drip, congestion, anosmia, headache, earache, tearing, red eyes, eye swelling, fatigue, drowsiness, and malaise [32].

The most commonly used methods of determining allergy to a particular substance are allergy skin testing (testing for immediate hypersensitivity reactions) and in vitro diagnostic tests, such as the radioallergosorbent test (RAST), which indirectly measures the quantity of antigen-specific IgE.