Rhinitis & Respiratory Tract Infection Flashcards
Define rhinitis.
Briefly describe the two types of rhinitis.
Rhinitis is defined as sneezing attacks, nasal discharge or blockage occurring for more than one hour on most days:
- For a limited period of the year (seasonal or intermittent rhinitis)
- Throughout the whole year (perennial or persistent rhinitis)
In which type of rhinitis do patients rarely have symptoms affecting the nose and throat?
Perennial rhinitis
How do B cells, IgE, mast cells, dendritic cells and T cells relate to allergic symtptoms?
B cells produce IgE antibody against the allergen.
IgE binds to mast cells via high affinity cell surface receptors, causing degranulation and release of histamine, proteases, prostaglandins, cysteinyl leukotrienes and cytokines.
This causes the acute symptoms of sneezing, itch, rhinorrhoea and nasal congestion.
Additionally, allergens are also presented to T cells via antigen presenting cells (dendritic cells). This causes a release of IL-4 and IL-3 which further stimulate the B cells. This also causes the response to change from Th1 to Th2, activating eosinophils, basophils, neutrophils and & T lymphocytes.
These cause chronic swelling and irritation leading too nasal obstruction.
What is the most common therapy for rhinitis?
Give examples
What are they most and least effective against?
H1 Antihistamines
E.g. loratadine, desloratadine, cetirizine and fexofenadine
They are particularly effective against sneezing and itching of the eyes and palate, but less effective against rhinorrhoea and nasal blockage
What are decongestants used for?
How do they work?
Give examples
What is special about prescription?
Used to treat nasal obstruction.
They work by mimicking sympathetic activity.
Examples - ephedrine nasal drops, xylometazoline, oxymetazoline
They are usually only prescribed for a limited time to open the nasal airways and allow better access to other local therapy, such as topical steroids.
Anti-inflammatory drugs
Give examples
How do they work?
What are they used for?
E.g. sodium cromoglycate, nedocromil sodium
Act by blocking an intracellular chloride channel and influencing mast cell & eosinophil activation, and nerve function.
They are used topically and are very effective in allergic conjunctivitis.
Corticosteroids
For each type give
Example(s)
When are they used?
Topical corticosteroids
- E.g. Beclomethasone
- Should be started before the beginning of seasonal symptoms
- The combination of topical corticosteroid taken with a non-sedative antihistamine is particularly effective
Oral corticosteroids
- E.g. predniolone
- If other therapy has failed, should be started on a short course (max 2 weeks)
Leukotriene antagonists
Example
When is it used?
E.g. Montelukast 10mg evening
Used in patients who do not respond to antihistamines or topical steroids (or a history of NSAID sensitivity)
Pharyngitis
What is the most common causative organism?
Symptoms?
Treatment?
Endemic adenovirus infection causes the common sore throat, in which the oropharynx and soft palate are reddened and the tonsils and inflamed and swollen.
It is self limiting, so only symptomatic treatment should be used.
Treatment for persistent and severe tonsillitis?
Phenoxymethylpenicillin 500mg QD
or
Cefaclor 250 mg TD
Amoxicillin and ampicillin should be avoided
Epiglottitis What causes this infection? Who does it usually affect? Symptoms? Management?
H. influenzae type b Hib)
Occurs in children under 5.
The child becomes extremely ill with a high fever.
Drooling is the common symptom.
This is a life threatening emergency and requires urgent endotracheal intubation and IV antibiotics e.g. ceftazidime.
The epiglottis, which is red & swollen, should not be inspected until facilities to maintain airways are available.
Influenza What types if infective organism and prevalence? Clinical features Complications Diagnosis and treatment
A & B - influenza A is associated with global pandemics; B is associated with localized outbreaks of mild disease.
Symptoms - fever, shivering, aching limbs, headache, sore throat and dry cough that persist for several weeks.
Secondary bacterial infection from Strep pneumoniae and H influenzae is common; secondary pneumonia from Staph aureus is rarer, but more serious.
Diagnosis can be established by demonstrating a four-fold increase in some antibody or by demonstrating virus in nasal secretions.
Treatment is bed rest & paracetamol, with antibiotics to prevent secondary infection in at risk groups.
Acute Bronchitis
Causative organism?
Symptoms?
Treatment?
Usually viral.
The illness begins with an irritating, non-productive cough, together with discomfort behind the sternum. There may be associated chest tightness, wheezing & SOB. Later the cough becomes productive with yellow or green sputum.
In otherwise health individuals the disease improves spontaneously within 4-8 days.
What diagnostic test is used for bronchiectasis?
HRCT –> “signet ring” sign, where bronchioles are wider than their accompanying arteries
Treatment of bronchiectasis?
Postural drainage - physiotherapists encourage patients to lie so that the affected lobes are uppermost at least 3 times daily for 20-30 mins.
Antibiotics are given.
Bronchodilators are useful in patients who demonstrate airflow limitation.
Inhaled/oral steroids can slow the progression of the disease.
