Etiologies of nasal obstruction: An overview

INTRODUCTION — Nasal obstruction, congestion, and other nasal symptoms are common complaints. There are numerous causes for nasal obstruction because of the complex anatomy of the nose and paranasal sinuses and the physiology of normal airflow through the nose.

This topic provides an overview of the basic anatomy of the nose and paranasal sinuses and reviews structural problems that result in nasal symptoms. Inflammatory conditions causing nasal symptoms and medications and systemic medical problems that cause rhinitis are reviewed separately. (See "An overview of rhinitis" and "Chronic nonallergic rhinitis" and "Chronic rhinosinusitis: Clinical manifestations, pathophysiology, and diagnosis".)

NASAL ANATOMY AND FUNCTION — A basic understanding of the anatomy of the nose and paranasal sinuses is essential for the clinician evaluating nasal symptoms.

Nose — The external nose is a pyramidal structure composed of skin, dorsal nasal bones, and upper and lower lateral cartilages (figure 1). In addition, the medial and lateral crura and columella contribute to the tip structure.

The internal anatomy of the nose includes the following important structures:

●The nasal septum is the midline structure, dividing the nose into two nostrils, and is composed of membranous, cartilaginous, and bony components (figure 1).

●The lateral nasal wall consists of the superior, middle, and inferior turbinates, which are erectile structures composed of mucosa and spongy bone, covered with mucous membrane (figure 2 and figure 3). The turbinates warm, humidify, and filter inspired air before its passage to the lungs. These structures swell or contract with changes in temperature, humidity, allergen exposure, and emotional perturbations. There is also a regular, cyclical pattern of turbinate swelling, which alternates between sides at intervals of two to five hours [1]. This is sometimes referred to as the nasal cycle.

●The internal nasal valve consists of the junction between the upper lateral cartilage and septum, while the external nasal valve includes the lower lateral cartilages (alar cartilages), columella, and nasal vestibule (figure 4).

Paranasal sinuses — The paranasal sinuses are paired, air-filled cavities located in the anterior midface (figure 5). Each of the sinuses has an ostium, a distinct bony opening, through which it drains. Although these structures are not part of the nasal airway, they play an important role in nasal symptoms, as disease processes involving the paranasal sinuses may lead to obstruction of sinus ostia and/or nasal cavity, with subsequent nasal congestion and obstructive symptoms.

●The maxillary sinuses are the largest sinuses and are located behind the cheeks (figure 5). They are roughly triangular in shape. The natural ostium is elliptical in shape and located along the superior medial wall of the sinus, within the ostiomeatal complex. Acute inflammation in the maxillary sinuses may cause the cheeks to become tender to touch or the upper jaw and upper teeth to ache.

●The ethmoid sinuses are located between the eyes, behind the bridge of the nose, and are composed of numerous small air cells that are filled with fluid at birth (figure 5). Pneumatization of the ethmoids begins at approximately one year of age. Inflammation of the ethmoid sinuses can cause pain between the eyes, tenderness along the sides of the nose, loss of smell, nasal congestion, and swelling of the periocular tissues.

●The frontal sinuses are positioned in the midface, over the eyes, and drain through the frontal recess into the hiatus semilunaris in the ostiomeatal complex (figure 5). Acute inflammation of the frontal sinuses can cause the forehead to be painful to touch. (See 'Ostiomeatal complex' below.)

●The sphenoid sinuses are located behind the eyes and nasal structures (figure 2). These structures are present at birth, although pneumatization begins around age three years and continues to develop through adulthood. Problems in the sphenoid sinuses may present with earache, deep aching at the top of the head, and neck pain.

Ostiomeatal complex — The ostiomeatal complex is a series of narrow, bony openings and clefts along the lateral wall of the nose and includes the middle turbinates, uncinate process, hiatus semilunaris, ethmoid bulla, and natural ostium of the maxillary sinus (figure 6).

The ostiomeatal complex serves as a common drainage pathway for the frontal, maxillary, and ethmoid sinuses and is critical for normal sinus drainage and ventilation. This important area frequently acts as a "bottleneck" when inflammation or other structural changes reduce its patency at various points (image 1). When there is obstruction of the complex from polyps, thickened mucosa, or mucus, the alteration in airflow and sinus ventilation results in the sensation of nasal stuffiness or fullness and facial pain, even though the nasal passage itself may be relatively patent. (See 'Normal airflow' below.)

Nasopharynx — The nasopharynx is located posterior to the nasal cavity, superior to the soft palate and oropharynx. The anterior border of the nasopharynx consists of the paired choanae, separated by the septum, which form the posterior border of the nasal cavity. The roof of the nasopharynx is the inferior wall of the sphenoid sinus (figure 2).

Important structures within the nasopharynx include the adenoid pad, Eustachian tube orifices, and the fossa of Rosenmüller, a slit-like depression medial to the Eustachian tube orifice (figure 2).

NORMAL AIRFLOW — Airflow through the nose begins at the entrance to the nostrils, a circular area defined by the nasal alae and columella. The negative pressure of inspiration draws air back through the nasal passage, to the choanae, and then into the larynx, trachea, and bronchi (figure 2).

During airflow through the nose, the turbinates, septum, and ostiomeatal complex contribute to natural turbulence of the air column. This turbulence is physiologically important because alteration of any of these internal structures can affect the perception of airflow. As an example, a person with a large septal perforation will have a constant sensation of nasal obstruction due to disruption of the normal turbulence patterns, even though the nasal passage itself is widely patent.

There is also airflow around the turbinates and into the natural ostia of the sinuses during normal respiration. Therefore, particles or allergens in the air can potentially affect both the nasal and sinus mucosa, resulting in inflammation throughout the upper airway.

CONGENITAL ABNORMALITIES — Congenital abnormalities that cause nasal obstruction, such as congenital pyriform aperture stenosis, choanal atresia, and deviation of the septum, may present emergently after birth as neonates are obligate nasal breathers (image 2) [2,3].

Less severely affected patients may present later in life with unilateral nasal discharge and/or obstruction. These disorders are reviewed in more detail elsewhere. (See "Congenital anomalies of the nose".)

ACQUIRED ABNORMALITIES — Acquired abnormalities include enlarged adenoids, foreign bodies, disorders of the nasal septum, abnormalities of the nasal valve, and nasal polyps. Neoplastic disorders are reviewed below. (See 'Tumors' below.)

Enlarged adenoids — A large adenoid pad is the most common cause of nasal obstruction in a child. Additional symptoms of adenoid hypertrophy include mouth breathing, mucopurulent nasal discharge, snoring, and potentially sleep-disordered breathing. (See "The pediatric physical examination: HEENT", section on 'Adenoidal hypertrophy' and "Mechanisms and predisposing factors for sleep-related breathing disorders in children".)

Prolonged mouth breathing due to adenoid hypertrophy may affect facial and dental growth and development, resulting in the characteristic "adenoid facies" (ie, open mouth, flattening and elongation of the midface, retraction of the upper lip, and narrowing of the hard palate resulting in crowding of the maxillary teeth). (See "Oral habits and orofacial development in children".)

Foreign bodies — Foreign bodies inserted into the nose may become lodged high in the nasal cavities or the paranasal sinuses. This is a common cause of both acute and chronic unexplained nasal symptoms in young children [4]. In acute cases, the child's parent or caregiver may be able to dislodge the object by mouth-to-mouth blowing, although items that have been in place for significant periods of time require surgical removal [5]. (See "Diagnosis and management of intranasal foreign bodies" and "Foreign bodies of the outer ear (pinna [auricle] and external auditory canal): Diagnosis and management".)

Disorders affecting the septum — One of the most common causes of nasal obstruction is an acquired deviation of the septum. The septum is easily injured, and even minor blunt trauma may cause alteration in the cartilage and/or bone of the septum. Traumatic or forceps delivery may result in damage to the septal cartilage at birth. Sports, motor vehicle accidents, and other traumatic events during a person's lifetime are common causes in older individuals. In addition, the normal aging process of cartilage will result in worsening of the deviation with time. Concomitant disease, such as allergic or vasomotor rhinitis or chronic rhinosinusitis, may potentiate the obstruction caused by a deviated septum.

Septal perforation is a condition often seen in those who use intranasal cocaine. It may also result from septal surgery, atrophic rhinitis, granulomatosis with polyangiitis, and several other disorders (table 1) [6-12]. It is difficult to know how commonly the various disorders cause septal perforation, as the literature largely consists of case reports and small series. Despite the apparent increase in airflow through a perforated septum, the patient actually experiences the sensation of nasal congestion. This is due to the alteration in the normal airflow through the perforated septum. Excess crusting and bleeding are also common in patients with septal perforation, further contributing to a sense of congestion and discomfort. (See "Granulomatosis with polyangiitis and microscopic polyangiitis: Respiratory tract involvement" and "Cocaine use disorder: Epidemiology, clinical features, and diagnosis".)

Nasal vestibulitis — Nasal vestibulitis, or nasal folliculitis, is an uncommon acute infection of the nasal vestibule, the area just inside the nostrils, usually with Staphylococcus. Precipitating factors include nose picking or excessive nose blowing, which can result in crusting and bleeding around the nasal hair follicles. Nasal vestibulitis has not been associated with nasal steroid use.

Prominent symptoms include pain and swelling, and the sudden onset of unusual tenderness upon touching or moving the nose generally prompts the patient to seek medical attention. Nasal obstruction is not usually reported. On examination, an area of swollen mucosa, crusting, or sometimes a pimple-like lesion on the nasal mucosa may be visible. The nose may appear swollen, erythematous, and warm externally in some cases, although fever is not usually present. The septum is not usually affected, because most of the hair follicles are located in the vestibular skin and mucosa.

Treatment consists of the application of warm compresses and topical mupirocin ointment applied intranasally twice daily for five days or oral antibiotics if the infection appears to be widespread.

Chronic nasal sores — Chronic nasal sores can be caused by a variety of inflammatory and infectious etiologies. Frequent nose picking or rubbing may lead to chronic infection of the nasal mucosa with Staphylococcus aureus, with development of ulceration, bleeding, and pain. Immunosuppressed individuals may develop infections from other bacteria, including Pseudomonas aeruginosa, and opportunistic microbes and viruses. Herpes simplex virus 1 may affect any mucous membrane, including oral cavity, lips, and nasal mucosa. Rarely, mycobacteria (tuberculosis, leprosy), syphilis, rhinoscleroma [13], and fungal infections affect the nose, with resulting chronic nasal sores. Intranasal drug use, such as cocaine, can lead to chronic nasal sores, ulceration, and eventual septal perforation.

Treatment of nasal sores includes topical antibiotic ointments, such as mupirocin, and appropriate oral antibiotics for severe infections. A culture of the lesion may be helpful in directing antibiotic therapy. Helpful adjunctive therapies include saline irrigations, local nasal care with warm compresses, and avoidance of digital manipulation.

A nasal sore which does not heal after such measures may require biopsy to establish a diagnosis of a more unusual systemic disease. Less common etiologies for nasal sores include granulomatous diseases, such as granulomatosis with polyangiitis and sarcoid. Rare diseases include lethal midline granuloma or sinonasal lymphoma [14,15]. (See "Clinical manifestations and diagnosis of sarcoidosis" and "Clinical manifestations, pathologic features, and diagnosis of extranodal NK/T cell lymphoma, nasal type" and "Granulomatosis with polyangiitis and microscopic polyangiitis: Clinical manifestations and diagnosis", section on 'Ear, nose, and throat involvement'.)

Abnormalities of the nasal valve — The internal nasal valve is formed by the junction of the upper lateral cartilage with the septum (figure 4). The external nasal valve is formed by the nasal alae and lateral crura.

The most common symptom of nasal valve weakness is nasal congestion, particularly with deep inspiration, because the negative pressure causes collapse of the nasal valve.

The most common cause of internal nasal valve weakness is iatrogenic, resulting from overzealous cartilage resection during rhinoplasty. The internal nasal valve may also be weakened by nasal trauma. External nasal valve weakness may be congenital or a result of traumatic injury. Correction of nasal valve weakness requires surgery using cartilage grafts to buttress and support the existing cartilage. A synthetic, bioabsorbable spreader graft implant has also been found to be effective in correcting nasal valve weakness [16].

Nasal polyps — Nasal polyps are abnormal, gray, glistening masses filled with inflammatory material, which may form in the nasal cavity or paranasal sinuses (picture 1). Polyps may be diagnosed clinically by their characteristic appearance on exam with a nasal speculum or rhinoscope. Polyps are also identifiable on computed tomography examination. In adults, nasal polyps are frequently associated with chronic rhinosinusitis, asthma, and aspirin sensitivity in the syndrome of aspirin-exacerbated respiratory disease (AERD). Some patients have concomitant allergic rhinitis or allergic fungal rhinosinusitis. In children, nasal polyps are most commonly associated with cystic fibrosis. (See "Aspirin-exacerbated respiratory disease" and "Cystic fibrosis: Clinical manifestations and diagnosis".)

Large or extensive polyps cause symptoms of nasal airway congestion or blockage, thick discharge, and anosmia. Surgery can offer temporary relief, although polyps tend to recur within a few months to years following this intervention alone. Continued medical management of the underlying etiology is therefore mandatory after surgery, including intranasal corticosteroids, allergen immunotherapy (if applicable), antileukotriene therapy, and daily lavage of the sinuses. In patients with AERD, aspirin desensitization followed by long-term daily therapy may be an additional therapeutic option. There are also biologics that can help reduce polyp size and symptoms burden, including dupilumab, omalizumab, and mepolizumab. (See "NSAIDs (including aspirin): Allergic and pseudoallergic reactions" and "Aspirin-exacerbated respiratory disease: NSAID challenge and desensitization" and "Chronic rhinosinusitis with nasal polyposis: Management and prognosis", section on 'Biologic therapies'.)

Mucoceles — Mucoceles are benign, epithelium-lined cysts filled with mucus, which can form in the paranasal sinuses. These structures may cause symptoms if sufficiently large or if exerting pressure on surrounding anatomic structures. Symptomatic mucoceles typically require surgical intervention.

The ethmoid and frontal sinuses are most commonly affected. Mucoceles in these areas may cause sinus obstruction, remodeling of the sinus bone, or deformation of the orbit or forehead (if very large). Similarly, sphenoid mucoceles may cause symptoms of headache, eye pressure, and retro-orbital pain.

In contrast, mucoceles in the maxillary sinus are less common and generally do not cause symptoms, unless they are very large and obstruct the ostiomeatal complex, resulting in postobstructive sinusitis.

Mucoceles should be differentiated from sinus retention cysts. Unlike mucoceles, sinus retention cysts do not result in expansion and thinning of the bony sinus walls. Sinus retention cysts are present in 8 to 30 percent of patients undergoing sinus imaging [17-19] and usually do not cause symptoms or compress surrounding structures, unless they are very large and causing mechanical obstruction of a sinus. One study found that cysts >20 mm and bilateral cysts were more likely to progress over time and cause symptoms [20]. However, most cysts do not change significantly over time, do not require serial imaging, and do not necessitate surgical removal [21-23].

TUMORS — Benign and malignant tumors in the nasal cavity and sinuses may cause nasal obstruction and discharge. Early symptoms may be vague and include nasal congestion or obstruction, mucoid drainage due to obstruction, retained secretions in the sinuses, and, rarely, bleeding.

Diagnosis is usually made by nasal endoscopy and biopsy. Referral to an otolaryngology specialist is indicated.

Benign — Benign tumors include inverted papilloma, which usually occurs on the lateral wall of the nose; other squamous papillomas; and, rarely, hemangiomas and hemangiopericytomas. (See "Pathology of head and neck neoplasms".)

Benign tumors of the nasopharynx can also cause symptoms of nasal obstruction. Juvenile nasal angiofibroma is a rare, benign tumor, accounting for 0.05 percent of head and neck tumors, which occurs almost exclusively in teenage males [24]. These tumors experience rapid growth during puberty. The triad of nasal obstruction, epistaxis, and nasal drainage is a common combination of signs and symptoms. Serous otitis media and diminished hearing also may be present. (See "Causes of epistaxis in children".)

Malignant — Malignant tumors in the sinonasal region are rare, accounting for less than 1 percent of all malignant tumors and 3 percent of malignant tumors of the upper aerodigestive tract [25,26].

Nasal congestion and discharge are common symptoms, which may be caused by an array of benign disorders. Consideration of a malignancy of the nasal or sinus cavities, however, should occur when these symptoms present in association with one or more of the following:

●Swelling or deformity of the nose or face

●Persistent facial, dental, ear, or neck pain

●Recurrent epistaxis or bloody nasal discharge in the absence of an obvious cause

●Visual changes, especially diplopia

●Neurologic changes, such as facial numbness or cranial nerve dysfunction

●Proptosis

●Neck mass or asymmetry of the face

●Trismus (ie, restricted ability to open the jaw)

●Unilateral pain with obstruction

Nasal cavity — Malignancies of the nasal cavity typically present with nasal obstruction, congestion, proptosis, visual changes, diplopia, facial pain or numbness, and bleeding. In late stages, cranial nerve palsies may develop due to invasion of the skull base.

Paranasal sinuses — Malignancies of the paranasal sinuses most commonly cause facial or dental pain, nasal obstruction, and epistaxis. Physical examination and radiographic studies are indicated when these symptoms occur in the absence of a clear cause in a patient over 40 years. The combination of pain with unilateral nasal obstruction should also prompt evaluation for malignancies. Growths involving the maxillary sinuses may cause dentures to become ill fitting. Ocular symptoms may occur with malignancies of the ethmoid sinus. (See "Overview of the diagnosis and staging of head and neck cancer".)

Specific malignancies

●The most common malignant tumor in the nasal cavity is squamous cell carcinoma. These patients usually present with nasal obstruction, sinusitis due to obstruction from the mass, and bleeding in early stages. Patients with late-stage carcinoma may have facial pain and/or numbness, visual changes, diplopia, proptosis, and bleeding. (See "Overview of treatment for head and neck cancer".)

●Malignant tumors may also occur in the numerous mucous glands of the respiratory epithelium and include adenocarcinoma and adenoid cystic carcinoma. When these tumors involve the nasal cavity or maxillary sinus, they can produce nasal obstruction, congestion, vision changes, or trismus. Minor salivary gland tumors involving the nasopharynx usually present at an advanced stage, often with invasion of the skull base, intracranial extension, and involvement of cranial nerves. (See "Salivary gland tumors: Epidemiology, diagnosis, evaluation, and staging".)

●Olfactory neuroblastoma is a malignant tumor that originates in the roof of the nose from the olfactory epithelium [27]. The most common symptom is unilateral nasal congestion or obstruction. Other presenting symptoms include nasal congestion, anosmia, recurrent epistaxis, pain, frontal headache, and diplopia. Physical examination may reveal a red-brown, polypoid mass located high in the nasal cavity. (See "Olfactory neuroblastoma (esthesioneuroblastoma)".)

●Melanomas rarely occur in the nose and paranasal sinuses and usually originate in the mucosa. Melanomas in the nose and paranasal sinuses usually present as a pigmented lesion in the mucosa, although amelanotic melanomas do occur. (See "Paranasal sinus cancer".)

●Nasopharyngeal carcinoma (NPC) presents with a mass in the neck in up to 90 percent of patients. Unilateral serous otitis media may occur due to Eustachian tube obstruction. Headache and cranial nerve abnormalities may be present at diagnosis. NPC is endemic in Southeast China, where it is associated with the Epstein-Barr virus, while the incidence is extremely low outside of these areas [28]. (See "Epidemiology, etiology, and diagnosis of nasopharyngeal carcinoma".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topics (see "Patient education: Deviated septum (The Basics)" and "Patient education: Nasal polyps (The Basics)")

SUMMARY

●Anatomy of the nose and sinuses – The anatomy of the nose and paranasal sinuses is complex. Important structures include the internal and external nasal valves, the nasal septum, the turbinates (erectile structures along the lateral wall that swell and contract in response to numerous stimuli), and the ostiomeatal complex (an area in which multiple structures interface and where the frontal, ethmoid, and maxillary sinuses drain into the nose) (figure 2 and figure 4 and figure 5 and figure 6). (See 'Nasal anatomy and function' above.)

●Normal airflow – During airflow through the nose, the turbinates, septum, and ostiomeatal complex contribute to natural turbulence of the air column. Alteration of any of these internal structures can affect the normal patterns of turbulence and result in the subjective sensation of congestion. (See 'Normal airflow' above.)

●Congenital causes of nasal obstruction – Congenital abnormalities that cause nasal obstruction, such as congenital pyriform aperture stenosis, choanal atresia, and congenital deviation of the septum, may present emergently after birth as neonates are obligate nasal breathers. (See 'Congenital abnormalities' above.)

●Acquired causes of nasal obstruction – Acquired structural causes of nasal symptoms include enlarged adenoids, foreign bodies, disorders of the nasal septum, abnormalities of the nasal valve, inflammatory conditions, nasal polyps, and neoplastic disorders. (See 'Acquired abnormalities' above.)

•In infants and small children, nasal trauma during delivery, adenoidal hypertrophy, and foreign bodies inserted into the nose are common causes of nasal symptoms. (See 'Acquired abnormalities' above.)

•In older children and adults, generalized swelling due to rhinitis, obstruction from septal disorders, nasal polyps, or overly aggressive sinus surgery are other structural causes of nasal symptoms. (See 'Acquired abnormalities' above.)

●Benign and malignant tumors – Benign and malignant tumors can also cause nasal symptoms, although these conditions are uncommon. Malignancies should be considered in patients who present with nasal symptoms accompanied by localized pain in the head or neck, numbness, bleeding, proptosis, diplopia, or cranial nerve abnormalities. (See 'Tumors' above.)