Sinusitis
Sinusitis, also known as rhinosinusitis and commonly known as a sinus infection, is an inflammation of the mucous membranes that line the sinuses resulting in symptoms that may include production of thick nasal mucus, nasal congestion, facial congestion, facial pain, facial pressure, loss of smell, or fever.
Sinusitis is a condition that affects both children and adults. It is caused by a combination of environmental factors and a person's health factors. It can occur in individuals with allergies, exposure to environmental irritants, structural abnormalities of the nasal cavity and sinuses and poor immune function. Most cases are caused by a viral infection. Recurrent episodes are more likely in people with asthma, cystic fibrosis, and immunodeficiency.
The diagnosis of sinusitis is based on the symptoms and their duration along with signs of disease identified by endoscopic and/or radiologic criteria. Sinusitis is classified into acute sinusitis, subacute sinusitis, and chronic sinusitis. In acute sinusitis, symptoms last for less than four weeks, and in subacute sinusitis, they last between 4 and 12 weeks. In chronic sinusitis, symptoms must be present for at least 12 weeks. In the initial evaluation of sinusitis an otolaryngologist, also known as an ear, nose and throat doctor, may confirm sinusitis using nasal endoscopy. Diagnostic imaging is not usually needed in the acute stage unless complications are suspected. In chronic cases, confirmatory testing is recommended by use of computed tomography.
Prevention of sinusitis focuses on regular hand washing, staying up-to-date on vaccinations, and avoiding smoking. Pain killers such as naproxen, nasal steroids, and nasal irrigation may be used to help with symptoms. Recommended initial treatment for acute sinusitis is watchful waiting. If symptoms do not improve in 7–10 days or worsen, then an antibiotic may be implemented or changed. In those in whom antibiotics are indicated, either amoxicillin or amoxicillin/clavulanate is recommended first line, with amoxicillin/clavulanate being superior to amoxicillin alone but with more side effects. Surgery may be recommended in those with chronic disease who have failed medical management.
Sinusitis is a common condition. It affects between about 10 and 30 percent of people each year in the United States and Europe. The management of sinusitis in the United States results in more than 11 billion in costs.
Signs and symptoms
Acute sinusitis can present as facial pain and tenderness that may worsen on standing up or bending over, headache, cough, bad breath, nasal congestion, ear pain, ear pressure or nasal discharge that is usually green in color, and may contain pus or blood.Dental pain can also occur. A way to distinguish between toothache and sinusitis is that sinusitis-related pain is usually worsened by tilting the head forward or performing the Valsalva maneuver.Chronic sinusitis presents with more subtle symptoms of nasal obstruction, with less fever and pain. Symptoms include facial pain, headache, night-time coughing, an increase in previously minor or controlled asthma symptoms, general malaise, thick green or yellow nasal discharge, feeling of facial fullness or tightness that may worsen when bending over, dizziness, aching teeth, and bad breath. Often, chronic sinusitis can lead to anosmia, the loss of the sense of smell.
A 2005 review suggested that most "sinus headaches" are migraines. The confusion occurs in part because migraine involves activation of the trigeminal nerves, which innervate both the sinus region and the meninges surrounding the brain. As a result, accurately determining the site from which the pain originates is difficult. People with migraines do not typically have the thick nasal discharge that is a common symptom of a sinus infection.
By location
The four paired paranasal sinuses are the frontal, ethmoidal, maxillary, and sphenoidal sinuses. The ethmoidal sinuses are further subdivided into anterior and posterior ethmoid sinuses, the division of which is defined as the basal lamella of the middle nasal concha. In addition to the severity of disease, discussed below, sinusitis can be classified by the sinus cavity it affects:- Maxillary – may cause pain or pressure in the maxillary region, often experienced as a toothache or headache.
- Frontal – may cause pain or pressure in the frontal sinus cavity, often experienced as a headache, particularly in the forehead area.
- Ethmoidal – may cause pain or pressure pain between or behind the eyes, along the sides of the upper nose, and headaches.
- Sphenoidal – may cause pain or pressure behind the eyes, though it is often felt at top of the head, over the mastoid processes, or the back of the head.
Complications
Orbital complications
The Chandler classification is used to group orbital complications into five stages based on their severity. Stage I, known as preseptal cellulitis, occurs when an infection develops in front of the orbital septum. It is thought to result from restricted venous drainage from the sinuses and affects the soft tissue of the eyelids and other superficial structures. Stage II, known as orbital cellulitis, occurs when infection develops behind the orbital septum and affects the orbits. This can result in impaired eye movement, protrusion of the eye, and eye swelling. Stage III, known as subperiosteal abscess, occurs when pus collects between walls of the orbit and the surrounding periosteal structures. This can result in impaired eye movement and acuity. Stage IV, known as orbital abscess, occurs when an abscess forms within the orbital tissue. This can result in severe vision impairment. Stage V, known as cavernous sinus thrombosis, is considered an intracranial complication. It can occur as bacterial spread progresses, triggering blood clots that become trapped within the cavernous sinus. This can result in previously described symptoms within the opposite eye and, in severe cases, meningitis.Intracranial complications
The proximity of the sinuses to the brain makes brain infections one of the most dangerous complications of acute bacterial sinusitis, especially when the frontal and sphenoid sinuses are involved. These infections can result from invasion of anaerobic bacteria through the bones or blood vessels. Abscesses, meningitis, and other life-threatening conditions may occur. In rare cases, mild personality changes, headache, altered consciousness, visual problems, seizures, coma, and even death may occur.Osseous complications
A rare complication of acute sinusitis is a bone infection, known as osteomyelitis, which affects the frontal and other facial bones. Specifically, the combination of frontal sinusitis, osteomyelitis and subperiosteal abscess formation is referred to as Pott's puffy tumor.Other complications
When an infection originating from a tooth or dental procedure affects the maxillary sinus it can lead to odontogenic sinusitis. Odontogenic sinusitis can often spread to nearby sinuses including the ethmoid, frontal, sphenoid sinuses, and the contralateral nasal cavity. In rare instances, these infections may spread to the orbit, leading to orbital cellulitis.
Causes
Acute
sinusitis is usually precipitated by an earlier upper respiratory tract infection, generally of viral origin, mostly caused by rhinoviruses, coronaviruses, and influenza viruses, others caused by adenoviruses, human parainfluenza viruses, human respiratory syncytial virus, enteroviruses other than rhinoviruses, and metapneumovirus. If the infection is of bacterial origin, the most common three causative agents are Streptococcus pneumoniae , Haemophilus influenzae , and Moraxella catarrhalis . Until recently, H. influenzae was the most common bacterial agent to cause sinus infections. However, introduction of the H. influenzae type B vaccine has dramatically decreased these infections, and now non-typable H. influenzae is predominantly seen in clinics. Other sinusitis-causing bacterial pathogens include S. aureus and other streptococci species, anaerobic bacteria and, less commonly, Gram-negative bacteria. Viral sinusitis typically lasts for 7 to 10 days.Acute episodes of sinusitis can also result from fungal invasion. These infections are typically seen in people with diabetes or other immune deficiencies and can be life-threatening. In type I diabetics, ketoacidosis can be associated with sinusitis due to mucormycosis.
Chronic
Definition and nomenclature
By definition, chronic sinusitis lasts longer than 12 weeks and can be caused by many different diseases that share chronic inflammation of the sinuses as a common symptom. It is subdivided into cases with and without polyps. When polyps are present, the condition is called chronic hyperplastic sinusitis; however, the causes are poorly understood. It may develop with anatomic derangements, including deviation of the nasal septum and the presence of concha bullosa that inhibit the outflow of mucus, or with allergic rhinitis, asthma, cystic fibrosis, and dental infections.Chronic rhinosinusitis represents a multifactorial inflammatory disorder, rather than simply a persistent bacterial infection. The medical management of chronic rhinosinusitis is now focused upon controlling the inflammation that predisposes people to obstruction, reducing the incidence of infections. Surgery may be needed if medications are not working.
During nasal endoscopy, an accessory maxillary ostium can sometimes be observed in the middle meatus. While not all are functionally active, in certain cases, mucus exiting the natural maxillary ostium may re-enter the sinus through the accessory ostium. This mucus recirculation may be associated with chronic maxillary sinusitis.
Attempts have been made to provide a more consistent nomenclature for subtypes of chronic sinusitis. The presence of eosinophils in the mucous lining of the nose and paranasal sinuses has been demonstrated in many people, and this has been termed eosinophilic mucin rhinosinusitis. Cases of EMRS may be related to an allergic response, but allergy is not often documented, resulting in further subcategorization into allergic and nonallergic EMRS.