Understanding Allergic Rhinitis: Causes, Symptoms, and Treatment

Acute rhinitis commonly results from viral infections but can also result from allergies, bacteria or other causes.

Allergic Rhinitis is an important topic of ENT paper. Read this blog post thoroughly to master it and scale up your NEET PG preparation.

• Rhinitis is defined as the inflammation and swelling of the mucous membrane of the nose characterized by a stuffy nose and runny nose and is typically brought on by the common cold or a seasonal allergy.

Allergic Rhinitis

• Allergic rhinitis is a reaction of your body when the body or your nose gets irritated by allergens, such as pollen, food, and other molecules causing allergic reactions.
• Allergy can be described as a multi-system disease because it can affect the nasal, skin, and eyes.
• Nasal allergy symptoms usually affect the upper and lower airway and co-exist with asthma called United airway disease (UAD).
• Allergy is the hypersensitivity reaction (type I IgE mediated reaction).

Pathology of allergy

There are two phases of allergy: Early phase and Late phase response.

Early phase response

• When the body is exposed to any allergen and allergen can be anything like an inhalant or ingested allergen.
• Allergen is taken up by dendritic cells, these dendritic cells present antigens to the T-cells  
• T-cells further proliferate into Th1 and Th2 cells   
• Th2 cells stimulate B-cell lymphocytes and B-cells produce immunoglobulin E or IgE
• Finally, IgE binds to the mast cell receptors which causes degranulation and release of inflammatory mediators (histamine, serotonin, leukotriene, prostaglandin)
• These inflammatory mediators are responsible for symptoms.

Etiology

• Inhalant allergen
• Ingestant allergen
• Genetic predisposition

Types of Allergy

Seasonal Allergy

• Only during a particular season is when pollen of plants released. Most occur in monsoon to winter when there is of allergen in the air during this transition period called seasonal allergic rhinitis. If the patient has symptoms throughout the year.  For example, an allergy to dust mites throughout the year is called a perennial allergy.

Clinical Features

• Cardinal Symptoms of seasonal allergy includes:
• Nasal symptoms- nasal obstruction, difficulty in breathing, excessive sneezing, itching in the nose, watery nasal discharge. Ocular symptoms- itching in the eyes. Skin symptoms- dryness in the skin, itching of the skin. Pulmonary symptoms- asthma, bronchospasm.

Occular Signs

• Oedema of lids. Congestion and cobble stone appearance of the conjunctiva. Dark circles under the eyes     

Nasal Signs

• Darier sign- Due to constant rubbing of the nose, the black line forms on the dorsum of nose is called the darier’s line.
• Salute sign - patient will keep on pushing and rubbing the nose upwards, it looks like a salute.

Otological Signs

• When there is an allergy, it causes nasal obstruction which results in the effect of ventilation to the eustachian tube, which can result in middle ear disease. Most common middle ear diseases- Retracted tympanic membrane or serous otitis media, secretory otitis media, and blue ear as a result of eustachian tube blockage. Air bubbles and air-fluid levels are the diagnostic criteria of serous otitis media.

Clinical investigations

Serum level of IgE

• Serum level of igE typically increased in patients with allergic rhinitis.

Total and differential counts

• The level of eosinophil is increased in patients with allergic rhinitis. Nasal smear shows a large number of eosinophils in allergic rhinitis.

Skin tests

• Skin tests help to identify the specific allergen by doing a skin prick test. In the skin prick test, multiple antigen injections (only common antigen injections) are given to the patient's forearm. When a wheel and flare reaction is seen, it indicates that the patient is allergic to a particular antigen. Disadvantages: It requires multiple pricks and risk of angioedema is there so it can be done in a hospital setting.

Radioallergosorbent test (RAST) or Invitro test

• It measures the specific IgE antibody concentration in the patient’s serum. This technique uses blood for investigation. At least 5-10 ml of blood is taken from the patient. This blood is put in various tubes which contain radio-labeled antigen substances like antigens against pollen, dust, and animal dander. Once the drop of blood is put into each of the test tubes and if the patient has allergic reactions and he/she would have IgE antibody against that antigen. If the patient is allergic to animal dander, the patient will have antibodies against the animal dander. So, when blood is put into the test tube for animal dander antigen, the antibody against animal dander will come and bind with animal dander antigen. As a result, the Ag-Ab reaction will occur. Because of the radio-labeled antigens, it shows immunofluorescence which explains that the patient has an allergy to animal dander. If the patient does not have an antibody, the antigen will not react with the antibody and no immunofluorescence will occur. Advantages: no pain, no injections, no chance of angioedema. Disadvantages: very costly because radio- labeled antigens are very costly.

Treatment

• Avoidance of allergens (ingestant allergens can be avoided but not inhalant allergens like pollens). Treatment with drugs: Nasal decongestants, Corticosteroids, Antihistamines, Anti-leukotrienes, Sympathomimetics, Mast cell stabilizers. Immunotherapy (Hyposensitisation):  Immunotherapy is the exposure of the patient to a known allergen from low dose to high dose. Immunotherapy suppresses the formation of IgE. So, the Ag-Ab complex is not formed and it is used when the allergic symptoms are very high. Suppose a patient is allergic to pollen but the patient can not avoid pollen every time. In this condition, an extract of pollen is given in a very small dose and then gradually increase the dose. As a result, immunity will be able to tolerate the pollen dose. This immunotherapy requires a prolonged period of time at least 1-3 years to develop tolerance to that particular allergen. It also raises the titer of specific Ig antibody. Types: Subcutaneous immunotherapy (SCIT) and Sublingual immunotherapy (SLIT).Subcutaneous immunotherapy (SCIT): An antigenic extract is given to the patient by subcutaneous route daily by increasing the dose gradually. Sublingual immunotherapy (SLIT): An antigen is given via a sublingual route in the form of drops that increases gradually. It is preferred method.

Complications

• Recurrent sinusitis
• Nasal polyps are usually ethmoid polyps
• Serous otitis media
• Orthodontic problems and other ill-effects of prolonged mouth breathing especially in children.
• Bronchial asthma

Vasomotor rhinitis or Non-allergic rhinitis

• When the symptoms are similar to allergy but serum IgE is normal, eosinophil count is normal called Vasomotor rhinitis. In other words, it is defined as allergic rhinitis but clinically stimulates nasal allergy with symptoms of nasal obstruction, rhinorrhea, and sneezing but the serum IgE level is normal.

Pathogenesis

• Vasomotor rhinitis occurs due to an imbalance of the sympathetic and non-sympathetic nervous system. The sympathetic nervous system is responsible for vasoconstriction. It shrinks the mucosa and paranasal sinuses size of the nose because of vasoconstriction and decreases the blood supply. As a result, the patient will have a wide airway. If vasoconstriction occurs in the mucosal glands, it will produce less mucus. The parasympathetic nervous system is responsible for vasodilation. Mucosa will become boggy because of vasodilation. As a result, the patient will have narrow space for breathing. If vasodilation occurs in the mucosal gland, it will increase the production of mucus. As a result, it will cause itching, running nose.

Clinical Features

• Paroxysmal sneezing 
• Excessive rhinorrhoea 
• Nasal obstruction 
• Post nasal drip

Treatment

Medical

• Antihistamines and oral nasal decongestants
• Topical steroids
• Systemic steroids can be given for a short period of time in very severe cases

Surgical

• Reduction of turbinates: Turbinates are responsible for the humidification and purification of the air. When turbinates of the nose become boggy, it causes difficulty in breathing and increases the discharge of mucus. In this condition, surgically reduce the size of turbinates. As a result, it will create a good space for the airway to breathe.
• Vidian neurectomy: Vidian nerve is formed by the greater superficial petrosal nerve and deep petrosal nerve. This vidian nerve is responsible for the autonomic innervation of the nasal cavity. If the autonomic innervation is cut off, the symptoms will disappear but it can cause dryness in the nose. Vidian neurectomy is done only in very advanced conditions when the symptoms are not controlled with medical therapy.

Rhinitis  Medicamentosa versus Drug-Induced Rhinitis

• Rhinitis  Medicamentosa: If the patient abuses decongestant drugs like xylometazoline and oxymetazoline (ɑ- adrenergic agonists). When the patient uses these drugs for a long period of time, it causes tolerance and rebound.

Rhinitis Medicamentosa Versus Drug Induced Rhinitis

• Drugs like Xylometazoline and Oxymetazoline (ɑ-Adrenergic Agonist) are responsible for vasoconstriction which may result in rebound nasal congestion. For the upregulation of receptor, the use of oxymetazoline, and xylometazoline should be ceased. So, short course of systemic steroids is given for the upregulation of receptors. As due to tolerance it causes down regulation of receptors. Down regulation of receptors will decrease adrenergic activity which causes increase in parasympathetic activity in nose and thus nasal congestion.
• If the drug as a side effect is causing rhinitis, then it is called drug-induced rhinitis.
• Guanethidine and Propranolol are known to cause rhinitis as a side effect ,causing drug induced rhinitis.
• For up regulation of receptors after the abuse of alpha adrenergic agonists a short course of systemic steroids is prescribed

Atrophic Rhinitis

• Atrophic rhinitis is a clinical term that causes progressive atrophy of the entire nose including mucosa, turbinates, septum, olfactory fibers, and paranasal sinuses. As a result, it causes a wide nasal cavity.  Nasal cavities are roomy and full of foul-smelling crusts. When air current goes through a wide nose, it causes crust inside the nose and the current will not go to the olfactory lobe. Because of the atrophy of olfactory fibres, the patient will not be able to smell. The patient will have Merciful Anosmia that causes a wide nasal chamber and crusting inside the nose. Atrophic rhinitis is classified into two types: Primary atrophic rhinitis and Secondary atrophic rhinitis. Various theories have been put for Primary atrophic rhinitis but exact cause is not known. Secondary atrophiic rhinitis is secondary tp infections like syphilis, lupus, leprosy, rhinoscleroma, radiotherapy to nose or excessive surgiical removal of turbinates or severe deviated septum.

Primary atrophic rhinitis theories

• Various theories have been put forward
  1. Hereditary: More than one member in the family are affected 
  2. Endocrine: The disease starts at puberty, involves females more than males disease tends to subside after menopause 
  3. Racial: American > Asian
  4. Nutritional deficiency: Vit A, Vit D or Iron
  5. Infective: Klebsiella Ozaenae (Perez bacillus)
  6. Autoimmune 

Clinical Features

• Merciful anosmia: Patient himself is unware of the smell due to marked anosmia.
• Patient may complain of nasal obstruction in spite of unduly wide nasal chambers.

Examination findings

• Nose
  • Filled with crusts.
  • Roomy cavities 
  • Atrophic pale mucosa 
  • Small turbinates 
• Paranasal sinuses: Small with thick walls
• Atrophic pharyngitis 
• Atrophic laryngitis

Medical Management

• Alkaline nasal douching solution 
• Nasal irrigation with an alkaline solution made by dissolving powder with sodium bicarbonate 1 part, sodium biborate 1part, sodium chloride 2 parts in 280 ml of water.
• 25% glucose in glycerine 
• Local antibiotics: Kemicetine antiozaena solution (chlormycetin, oestradio, vitamin D2)
• Oestradiol spray: increase vascularity 
• Placental extract submucosal injection 
• Systemic streptomycin
• Potassium iodine
• To avoid dryness and crusting in the nose, irrigation of the nose with certain solutions is suggested to keep the nose clean and moist.
• Alkaline nasal douching solution: This solution is used to irrigate the nose with the help of a nasal wash bottle. 

Surgical Management

• Youngs operation: Mucosal flaps are elevated to close nasal cavity 
• Narrowing of nasal cavity:
  1. Submucosal injection of Teflon
  2. Lautenslagers operation- Section and medial displacement of lateral wall of nose.
  3. Insertion of fat, cartilage, bone under mucoperiosteum of floor and lateral wall of nose.
• Young's operation: This procedure involves elevating the mucosa across the vestibule or the inlet of the nose (completely close the nose) from medially, laterally, and suture altogether.
• Modified Young's operation: It made an opening of 10mm close to the rest of the nasal cavity.
• Narrowing of the nasal cavity:  To reduce a large amount of current to the nose, and to reduce crust.
  1. Subcutaneous injection of Teflon to the lateral walls of the nose so that the nose becomes narrow.
  2. Lautenslagers operation:  Fracture the lateral wall and push it towards the midline.

Rhinitis Sicca

• Rhinitis sicca occurs in those people who expose to hot-dry climates, typically seen in people who work in bakeries.

Rhinitis Caseosa (Nasal Cholesteaoma)

• It occurs due to the obstruction of sinuses to sinusitis. So, sinuses will not be able to drain the secretions. As a result, there will be a retention of secretion in the sinuses. Once it causes chronic retention of a secretion at the sinuses, it will form a waxy, sebaceous, sticky mass inside the nose called rhinitis caseosa. Usually seen in males
• Unilateral
• Treatment is debriding the tissue and treating the cause.

Important Questions

Q. Which infection is responsible for primary atrophic rhinitis? 

Ans: Klebsiella Ozaenae (Perez bacillus)

Q. Rhinitis caseosa occurs due to the

Ans: Obstruction of the sinuses to sinusitis

Q. Vidian nerve is formed by the 

Ans: Greater superficial petrosal nerve and deep petrosal nerve

Q. Nasal allergy symptoms usually affect the upper and lower airway and co-exist with asthma called as

Ans: United airway disease (UAD)

Q. Allergy is the hypersensitivity reaction mediated by

Ans: Type I IgE-mediated reaction

Q. IgE binds to the mast cell receptors which causes degranulation and release of inflammatory mediators 

Ans: Histamine, serotonin, leukotriene, prostaglandin

Q. Rhinitis sicca occurs in those people who are exposed to

Ans: Hot-dry climates, typically seen in people who work in bakeries

Q. Young’s operation is the surgical treatment of

Ans: Atrophic rhinitis

Q. Allergic shiner is a feature of 

Ans: Seasonal rhinitis

Q. Drugs like Xylometazoline and Oxymetazoline are responsible for

Ans: Vasoconstriction may result in rebound nasal congestion

Q. Merciful Anosmia  is the clinical feature of

Ans: Atrophic rhinitis

Q. Guanethidine and Propranolol are known to cause 

Ans: Rhinitis as a side effect

Q. Alkaline nasal douching solution is used to irrigate the 

Ans: Nose with the help of nasal wash bottle

And that is everything you need to know about Acute Chronic Rhinitis for your ENT preparation and NEET PG exam preparation. For more informative and interesting posts like this, download the PrepLadder App and keep following our blog!