Overview

Nasal congestion causes impaired airflow through the nose and is accompanied by pressure and mucus.¹ Rhinitis is a reaction that occurs in the nasal mucosa as a result of exposure to allergens such as pollen, dust, infections, and medications.² Nasal congestion is one of the common symptoms of rhinitis, other symptoms include sneezing, itchiness, and blocked or running nose.³ It is important to understand the connection between the two to achieve optimal relief when allergies arise. Rhinitis symptoms cause significant irritation to patients with negative effects on quality of life and sleep, productivity, and overall health.²

Nasal congestion

Nasal congestion is a symptom common to both allergic and nonallergic rhinitis as well as colds and other infections.⁴ The congestion itself occurs for many reasons including mucosal inflammation and swelling, nasal secretions, and dilation of blood vessels (vasodilation), as well as structural problems such as septal deviation and cleft palate.⁴ Inflammation physically occludes the nasal passages leading to the feeling of insufficient airflow. The blood vessels in the nose will dilate and start to leak fluid - this is what leads to a runny nose.⁵ 

Nasal congestion can be caused by viruses and bacteria, when these infections take hold in the nose, they attack the lining of the nose causing inflammation that leads to that congested feeling.⁶ Congestion is also often coupled with mucus production, mucus functions to protect the airways by trapping foreign invaders that are causing the infection, and whilst annoying is an important immune defence mechanism.⁷

Allergic rhinitis

Allergic rhinitis is suggested to affect around 20% of the UK population.² Allergic rhinitis is a common condition that is characterised by sneezing as well as nasal itching, congestion, and discharge. Allergic rhinitis is more common in higher income countries and is a significant health burden to the patient and on a global scale. ⁸ Allergic rhinitis is a response caused by a type of antibody known as IgE. It can often be diagnosed by symptoms alone but can also be confirmed by skin prick tests or blood tests for allergen specific IgE.⁸ Allergic rhinitis can be either seasonal or perennial. Seasonal rhinitis symptoms occur in spring, summer, and early autumn, and this is usually as a response to pollens and spores from grass, trees, and weeds. Perennial rhinitis symptoms occur all year round, they are caused by other non-seasonal common allergens such as dust mites, pet hair, dander, etc.⁹

How does an allergen cause these symptoms?

In a sensitive person, an allergen will come into contact with the cells that line the nasal passages. These cells will release small molecules and these molecules will start the cell signalling for allergy-like symptoms to develop. Cytokines are a key type of molecules in this pathway and they lead to inflammation and immune responses.⁸

People with allergic rhinitis are described as sensitive to allergens, meaning that the body responded to an allergen once, causing an immune response and now whenever this patient comes into contact with said allergen, the same response will be amassed, possibly for the rest of their lives. When a person comes back into contact with the allergens again, the cells of the immune system recognise the allergen and trigger activation of more immune cells, importantly immune cells that produce IgE specific to that allergen. IgE is then free to bind to the allergens and to other immune cells at the same time such as mast cells and basophils. These mast cells and basophils release chemicals such as histamine that case the symptoms of allergic rhinitis.⁸

The link between allergic rhinitis and nasal congestion

For a patient sensitive to allergens when they come into contact with these allergens the immune system kicks into action, the IgE and mast cell and basophil responses discussed above. Histamine released by mast cells is responsible for the vasodilation and vascular permeability seen in the nasal passages that attributes to the nasal congestion and secretions.⁴ There are also many other chemicals released by the mast cells and basophils that contribute to nasal congestion. Prostaglandin D2 is another chemical released that is suggested to play a role in the inflammation of the lining of the nose.⁴

As well as mast cells and basophils, eosinophils are another key type of immune cell responsible for the responses during allergic rhinitis. They infiltrate the area in the nose and airways and release even more chemicals that exacerbate the allergy symptoms.⁴ The number of eosinophils in the nasal cavity has been shown negatively correlate with the ease of airflow through the nasal passages of patients with allergic rhinitis.¹⁰

Long term complications can arise as a result of allergic rhinitis. These can include nasal polyps, sinusitis, or blockage of the middle ear.³

Non-allergic rhinitis 

Non-allergic rhinitis is another cause of nasal congestion. It presents with the same symptoms as allergic rhinitis but has a different cause. Non-allergic rhinitis is generally caused by viruses or irritants but not allergens. Other causes include having a cold, exercising, hormonal changes, and certain medications such as beta blockers, ACE inhibitors, and anti-inflammatory painkillers.¹¹ Symptoms of nonallergic rhinitis are cough, low-grade fever, nasal congestion, nasal secretions, and sneezing.¹²

Treatment options and management strategies 

Nasal congestion can be treated at home with a class of medicines known as decongestants. These can be in different forms such as nasal sprays, drops, tablets, or liquids. Sometimes decongestants can contain other medicines such as painkillers and antihistamines to relieve the pain associated or to treat the root cause of the congestion. They work by reducing the swelling in the blood vessels of your nose. These can be bought over the counter usually and will treat the symptoms of both allergic and non-allergic rhinitis.¹³

Allergic rhinitis can be treated by antihistamines, these work by blocking the effects of histamine and thus, reduce the swelling, inflammation, and permeability of the blood vessels and nasal passages. Antihistamines can be bought over the counter or prescribed at higher doses from your doctor.³

In some cases, intranasal corticosteroids will be prescribed for patients with severe or persistent symptoms of allergic rhinitis. These medicines exert their anti-inflammatory effects on the mucosal cells of the nose, therefore, relieving congestion. Importantly because these corticosteroids are introduced nasally, they are not absorbed, there are generally no systemic side effects. In certain cases antihistamines and intranasal corticosteroids can be combined for optimal relief.⁴

Summary

Rhinitis comes hand in hand with nasal congestion as well as other irritating nasal symptoms such as itching, running, and sneezing. Caused by allergens, infections, medications or others, rhinitis can be a frustrating and life-altering condition. If these symptoms are having a significant impact on your life it is important to seek medical attention to better understand your treatment options. Managing the symptoms and understanding the causes can lead to an improved overall well-being.