Rhinitis (Pathology of Respiratory System)

 

Rhinitis is inflammation and swelling of the mucous membrane of the nose, characterised by a runny nose and stuffiness and usually caused by the common cold or and an allergy.

The nose is the most commonly infected part of the upper airways. Rhinitis may be acute or chronic. Acute rhinitis commonly results from viral infections but may also be a result of allergies or other causes. Chronic rhinitis usually occurs with chronic sinusitis (chronic rhinosinusitis).

Viral Rhinitis

• Acute viral rhinitis (the common cold) can be caused by a variety of viruses
• Symptoms consists of runny nose, congestion, post nasal drip, cough, and a  low-grade fever.
• Stuffiness can be relieved by taking phenylephrine as a nasal spray or pseudphedrine by mouth. These drugs, available by over the counter, cause the blood vessels of the nasal mucous membrane to constrict. Nasal spray should only be used for only 3 or 4 days because  after that period of time, when the effects of the drugs wear off, the mucous membrane often swells even more that before. This phenomena is called as rebound congestion.
• Antihistamines help  control runny nose but cause drowsiness and other problems, especially in older people.
• Antibiotics are not effective for acute viral rhinitis.

Allergic Rhinitis

• Allergic rhinitis is caused by a reaction of the body's immune system to an enviromental trigger. The most common environmental triggers include dust, molds, pollens, grasses, trees, and animals.
• Symptoms include sneezing, runny nose, stuffiness, and itchy, watery eyes.
• A doctor may diagnose  allergic rhinitis based on a person's history of symptoms. Often, the person has a family history of allergies.More detailed information may be obtained using blood tests or skin testing.
• Avoiding the substance that triggers the allergy prevents symptoms but is often not possible.
• Nasal corticosteroid sprays decrease nasal inflammation caused by many sources and are relatively safe for long-term use.
• Antihistamine help prevent the allergy reaction and thus symptoms.
• Antihistamines dry the mucous membrane of the nose but many of them also cause sleepiness and other problems, especially in older  people.
• Never ones require a prescription but do not have these side effects.
• Allergy shots (desensitization) help to build long therm tolerance to specific  environmental triggers, but they may take months  or years to become fully effective.
• Antibiotic do not relieve the symptoms of allergic rhinitis.

Atrophic Rhinitis

• Atrophic rhinitis is a form of chronic rhinitis in which  the mucous membrane thins (atropies) and hardens, causing the nasal passages to widen and dry out.
• The cells normally found in the mucous membrane of the nose - cells that secrete mucus and have hairlike projections to move dirt particles out - are replaced by cells like those normally found in the skin.
• The disorder can develop in someone who had sinus surgery in which a significant amount of intranasal structures and mucous membranes were removed. 
• A prolong bacterial infection of the lining of the nose is also a factor.
• Crust form inside  the nose, and an offensive odour develops.
• A person may have recurring severe nosebleeds and can lose his sense of smell (anosmia).
• Treatment is aimed at reducing the crusting, elimination the odour, and reducing infections. 
• Topical antibiotics, such as bacitracin applied  inside the nose, kill bacteria.
• Estrogens and vitamins A and D sprayed into the nose or taken by mouth may reduce crusting by promoting mucosal secretions.
• Other antibiotics, given by mouth or intravenously, may also be helpful.
• Surgery to narrow the nasal passages may reduce crusting became the decreased airflow prevents drying if the thinned mucous membrane

Vasomotor Rhinitis

• Vasomotor rhinitis is a form of chronic rhinitis.
• Nasal stuffiness, sneezing, and a runny nose - common allergic symptoms - occur when allergies do not appear to be present.
• In some people, the nose reacts strongly to irritants, perfumes, and pollution.
• The disorder comes and goes but is worsened by dry air.
• The swollen mucous membrane varies fro bright red to purple.
• Sometimes, people also have slight inflammation of the sinuses.
• When persistent, endoscopy of the nose or CT scan of the sinus is not significant.
• Treatment is aimed at relieving symptoms.
• Avoiding smoke and irritants and using a humidified central heating system or vaporizer to increase humidity may be beneficial.
  

Related article :

1. Sinusitis
   

Sinusitis (Pathology of Respiratory System)

Sinusitis is inflammation of the sinuses, most commonly caused by an allergy or infection.

Sinusitis is one of the common medical conditions. About 10 to 15 million people each year develop symptoms of sinusitis. Sinusitis may occur in any of the four groups of sinuses; maxillary, frontal, ethmoid, and sphenoid. Sinusitis nearly always occurs in conjunction with inflammation of the nasal passages (rhinitis), and some doctors refer the disorder as rhinosinusitis. It may be acute disorder or chronic.

Acute: Acute sinusitis may be caused by a variety of bacteria and often develops after something blocks the openings of the sinuses. Such blockage commonly results from a viral infection of the upper airways, such as common cold. During a cold, the swollen mucous membranes of the nasal cavity tend to block the openings of the sinuses. Air in the sinuses is absorbed into the bloodstream, and the pressure inside the sinuses decreases, cause pain and drawing fluid into the sinuses.The fluid is a breeding ground for bacteria. White blood cells and more fluid enter the sinuses to fight the bacteria; this influx increases the pressure and cause more pain.

Allergy also cause mucous membrane swelling, which blocks the openings to the sinuses. Additionally, people with a deviated septum are more prone to obstructed sinuses.

Chronic: Sinusitis is defined as chronic if it has been ongoing for more than 8 to 12 weeks. Doctors do not understand exactly what causes chronic sinusitis but it may follow a viral infection , a severe allergy, or exposure to an environmental pollutants. Often the person has a family history; a genetic predisposition appears to be a factor. If the person has a bacterial or fungal infection, the inflammation is much worse. Occasionally, chronic sinusitis of the maxillary sinus results when an upper tooth abscess spreads into the sinus above.

Symptoms and Diagnosis

• Acute sinusitis usually results in pain, tenderness, and swelling over the affected sinus.
  
• Maxillary sinusitis produces pain over the cheeks just below the eyes, toothache, and headache.
  
• Frontal sinusitis produces headache over the forehead.
  
• Ethmoid sinusitis produces pain behind and between the eyes and headche, often described as splitting over the forehead.
  
• The pain produced by sphenoid sinusitis does not occur in well-defined areas and may be felt in the front or back of the head.

In acute sinusitis,

• Yellow or green pus may be discharge from the nose.
  
• Fever and chills also can occur, but their presence ma suggest that the infection has spread beyond the sinuses.
  
• Any change in vission of swelling around the eye is a very serious condition that can quickly-within minutes to hours -result in blindness. Such a change should be evaluated by a doctor as soon as possible.

The symptoms of chronic sinusitis are usually much more subtle, and pain occurs less often. The most common symptoms of chronic sinusitis are

• Nasal obstruction,
  
• Nasal congestion,
  
• Post-nasal drip.
  
• The person also may feel generally ill (malaise).

A doctor makes the diagnosis based on the typical sysmptoms and sometime, on x-rays studies. X-rays may show fluid in the sinuses, but CT scan is able to determine the extent and severity of sinusitis. If a person has maxillary sinusitis, the teeth may be x-rayed to check for tooth abcesses. Sometimes a doctor passes an endoscope into the nose to inspect the sinus openings and to obtain samples of fluid for culture. This procedure, which requires a local anesthetic, can be done in the doctor's office.

Chronic Right Maxillary Sinusitis

on Computerized Tomography (C.T. Scan

Treatment

• Treatment of acute sinusitis is aimed at improving sinus drainage and curing the infetcion.
  
• Nasal sprays, such as phenylephrine, which cause blood vessels to narrow can be used for a limited time.
  
• Similar drugs, such as pseudoephedrine, taken orally are not as effective.
  
• For both acute and chronic sinusitis, antibiotics such as amoxicilin, or trimethroprim-sulfamethoxazole are given, but people who have chronic sinusitis take antibiotics for a longer period of time.
  
• Nasal corticosteroid sprays and corticosteroid tablets are helpful in reducing the inflammation in the mucous membranes.
  
• If significant allergy symptoms are present, antihistamines may be useful.
  
• Nasal irrigations with salt water can help to cleanse the sinuses and keep them moist. When antibiotics are not effective, surgery may be performed either to wash out the sinus and obtain material for culture or to improve sinus drainage, which allows the inflammation to resolve.

Related article:

1. Rhinitis

Further reading:

1. emedicine (sinusitis)
   

Introduction to Pathology (1st lecture)

Lecture by Dr Karim
1st lecture of Pathophysiology of Respiratory System
7/7/2008

PATHOLOGY
-the study of diseases
-the study of disease process, and the associate functional dan structural changes in tissues and organs

PATHOGENESIS (why + how)
-mechanism by which organic disease occurs

LESSIONS (what)
-structural changes or alteration of tissues

PATHOPHYSIOLOGY
-the study of alteration of functions as a consequence of disease
the study of functional consequences of a diseased organ

ALTERATION OF FUNCTION
-increased ==> hyperfunction
-decreased ==> hypofunction

(vital organ)

insufficiency===>failure======>DEATH

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