Sinusitis is caused by the obstruction of the paranasal sinuses. Swelling of the mucosa obstructs the ostium of the ostiomeatal complex, which is continuous with the nasal mucosa and the mucosa of the sinuses. This impedes the drainage and ventilation of the sinuses, causing pressure and pain and creates a breeding ground for micro-organisms. Generally, sinusitis starts with a viral infection of the nasal mucosa. Rhinosinusitis refers to inflammation in the nasal cavity and paranasal sinuses. Bacterial superinfection in the sinuses is possible and more common in patients consulting the GP for their symptoms.
Usually, several sinuses are inflamed at the same time, with the maxillary sinus almost always being affected. Isolated inflammations of sinus frontalis, ethmoidalis and sphenoidalis are rare. Facilitating factors are anatomic variations (e.g. palatoschisis, previous surgery of the nose or sinuses), allergies and smoking.
Symptoms can be (unilateral) facial pain or pressure, pain or pressure in the sinuses (which increases when bending over), tooth or molar pain, affected smell and headache. The diagnosis can be made based on history taking and the presence of at least one of these symptoms, in addition to nasal congestion or purulent rhinorrhoea. Temperature might be subfebrile. It is not necessary for diagnosis to obtain pus from a sinus, or to prove sinusitis radiologically. Acute rhinosinusitis lasts less than four weeks.
Chronic rhinosinusitis is an inflammation of the paranasal sinuses and the linings of the nasal passages that lasts 12 weeks or longer. This may present abruptly, starting as acute sinusitis or nonspecific upper respiratory infection that fails to resolve, or it may develop slowly, over months or years. In adults, it is often accompanied by nasal drainage, nasal congestion, facial pain or pressure, and a reduction or loss of the sense of smell. Children with chronic rhinosinusitis may cough instead of having a diminished sense of smell. Three subtypes of chronic rhinosinusitis can be distinguished: a subtype with nasal polyposis, a subtype without nasal polyposis and allergic fungal rhinosinusitis.
The treatment of acute rhinosinusitis is focused on symptom relief. Analgesics play an important role, since pain seems to be the major nuisance and often negatively impacts daily functioning. Decongestants can provide relief for the nasal obstruction complaints. Antibiotics are commonly prescribed but often unnecessary, since they only have a small effect on recovery, while side effects and resistance may occur. In the context of the Dutch healthcare system, where continuous GP care is readily accessible and patients can return to the same GP (practice) in case of persistent or worsening symptoms, GPs can apply ‘watchful waiting’ and prescribe antibiotics at a later time if necessary. The Dutch Royal College of General Practitioners advises to prescribe antibiotics in exceptional cases only. Their guideline focuses on acute rhinosinusitis and provides no specific treatment advice for the chronic variant. International treatment recommendations for chronic rhinosinusitis include the use of intranasal corticosteroids and other options that can be performed after referral, e.g. endoscopic surgery.
In ICPC-2, acute / chronic (rhino)sinusitis is coded R75. Based on the ICPC-2 data, the distinction between acute or chronic rhinosinusitis cannot be made.
‘Headache’ (N01), ‘facial pain’ (N03) or ‘upper respiratory tract infection’ (R74) can be coded when criteria of an acute / chronic rhinosinusitis are not met.
Rhinosinusitis has an incidence of 8.9 per 1000 patient years, meaning there are on average nine new diagnoses of rhinosinusitis per 1000 patients each year. The incidence is highest in the age group 25-44. Link/Figure 1
The prevalence of rhinosinusitis is 11.7 per 1000 patient years, meaning that among 1000 patients in a year, 12 persons seek help from their GP for rhinosinusitis. In the age group 25-44, the prevalence is highest (18.0 per 1000 patient years). Link/Figure 2
The numbers for women are almost double to those for men, both for incidence of rhinosinusitis (new diagnoses, Link/Figure 1) and for prevalence (affected persons, Link/Figure 2). The higher prevalence compared to incidence indicates that rhinosinusitis sometimes requires GP attention during more than one calendar year. Some episodes that run across the calendar year border may be chronic rhinosinusitis.
The most common initial reason for encounter (RFE) for rhinosinusitis is ‘rhinosinusitis’ (R75), which means that the condition is easily self-diagnosed. Other frequent reasons for encounter are symptoms of the sinus (R09) and upper respiratory tract infection (R74). Link/Table 3 Headache (N01) is the most common RFE in patients younger than 25, who may less often recognise the symptoms from previous episodes. Link/Table 4
The most common GP intervention coded for rhinosinusitis is the prescription of medication. In 73% of episodes, GPs prescribe medication during the episode of rhinosinusitis. A referral to a medical specialist is recorded in only 6% of the episodes of rhinosinusitis. Link/Table 5
It is interesting to know what specific medication is prescribed since, in most episodes of rhinosinusitis, ‘some’ prescription occurs. Intranasal corticosteroids (R01AD) are prescribed in 37% of episodes. Different classes of antibiotics are prescribed: tetracyclins (J01AA, including doxycycline), in 18%, penicillins (J01CA, including amoxicillin), in 16%; and macrolides (J01FA, including azithromycin), in 3%. Link/Table 6
The Dutch primary care guideline on rhinosinusitis was updated in 2014, stating that (1) antibiotics are not recommended in (single episodes) of rhinosinusitis, including in cases where the symptoms do not improve after 14 days, and (2) macrolides have no place in the treatment of rhinosinusitis anymore due to resistance problems.
The FaMe-Net prescription data for rhinosinusitis show clearly declining percentages of prescribed antibiotics from 2015 onwards. It is possible to adjust the calendar years on the website to see prescription rates in a selected time period. Since 2016, penicillins have taken over the first position of prescribed antibiotic types from tetracyclins, in line with the 2014 guideline. Link/Table 7
The Dutch rhinosinusitis guideline furthermore advises to (3) consider intranasal corticosteroids only in prolonged or recurring episodes of rhinosinusitis. After 2014, the percentages of prescribed intranasal corticosteroids (R01AD) gradually increase, which may be related to the declining antibiotics prescription rates. Link/Table 7
Dutch guideline: https://richtlijnen.nhg.org/standaarden/acute-rhinosinusitis#volledigetekst (2014)
Patel ZM, Hwang PH. Acute sinusitis and rhinosinusitis in adults: Clinical manifestations and diagnosis. In: UpToDate, Deschler DG, File TM, Givens F, Bond S (Eds), UpToDate, Waltham, MA, 2022
Holbrook EH. Chronic rhinosinusitis: Clinical manifestations, pathophysiology, and diagnosis. In: UpToDate, Peters AT, Deschler DG, Feldweg AM (Eds), UpToDate, Waltham, MA, 2023