Allergic disorders Flashcards
What is the treatment for allergic rhinitis (seasonal allergies)?
- Antihistamines
- Decongestants
- Intranasal corticosteroids (most consistent relief)
(or any combination thereof) - In severe cases, systemic corticosteroids
- Avoidance of the trigger is always indicated (if possible_
How long should topical decongestants (nasal sprays, like Afrin) be used?
- Topical decongestants should be used for only 5-7 days and can cause rebound congestion (ie “nasal spray addiction” as you need more spray or continued use to get the same effect)
What physical exam signs are consistent with allergic rhinitis?
- Swollen/boggy nasal turbinates that are pale and blue-gray in color
- Thin and watery secretions
- Itchy eyes
- Nasal congestion/discharge
- Seasonal in nature
What mediators are released in allergic rhinitis?
- Histamine, tryptase, chymase, kinase, leukotrienes, and prostaglandin D2
- Leads to mucus gland stimulation (increased secretion), vasodilation (congestion), sensory nerve stimulation ( sneezing and itching)
What symptoms are associated with allergic rhinitis?
- sneezing
- itching (of nose, eyes, or ears)
- rhinorrhea
- post nasal drip
- congestion
- anosmia
- headache/earache
- tearing
- red eyes
- drowsiness
What are causes of a deviated septum?
- Chronic rhinitis
- Granulomatous disease
- Cocaine abuse (snorting)
- Prior surgery
- Topical decongestant abuse
What is perennial allergic rhinitis typically caused by?
- Typically caused by allergens in the home (ie dust mites and animal dander)
What is the role of antihistamines in treating allergic rhinitis?
- Antihistamines competitively antagonize the receptors for histamine, which is released from mast cells
- reduces symptoms
- Diphendyramine, chlorpheniramine, hydroxyzine (all otc)
- More expensive, less CNS penetration: loratadine, fexofenadine, cetirizine
What are side effects of antihistamines?
- dry mouth/eyes, blurred vision, urinary retension
What is the mechanism of action of nasal decongestants?
- Constrict blood vessels in the nasal mucosa and reduce the overall volume of the mucosa
- Most common is pseudoephedrine, an alpha adrenoreceptor agonist
What are the side effects of oral decongestants?
- Tachycardia, tremors, and insomnia
- Rebound hyperemia and worsening of symptoms can occur with chronic use
What treatment is most effective in the long term management of allergic rhinitis?
- Corticosteroid nasal sprays => reduce production of inflammatory mediators and the recruitment of inflammatory cells
- Systemic absorption is relatively low (reduces side effects)
What side effects are associated with corticosteroid nasal sprays?
- Nosebleeds, pharyngitis, and URIs
What treatment is effective for both allergic rhinitis and as maintenance therapy for persistent asthma?
- Leukotriene inhibitors (montelukast, zafirlukast, and zileuton)
What is the danger of long term oral corticosteroid use for severe rhinitis?
- Suppression of the hypothalamic-pituitary-adrenal axis
- Hyperglycemia
- Peptic ulcer formation
- Increased susceptibility to infection, poor wound healing, and reduction of bone density
What therapy is used in patients who remain symptomatic despite maximal medical therapy?
desensitization therapy
What is angioedema?
- Painless, deep, subcutaneous swelling that often involves the periorbital, circumoral, and facial regions
At the first suspicion of anaphylaxis, what should be given?
- Aqueous epinephrine 1:1,000 in a dose of 0.2-0.5ml (or mg) injected subcutaneously or IM, can be given every 15 minutes
- IV fluid to replace loss of intravascular plasma into tissues
- Endotracheal intubation may be required if airway obstruction
- Bronchospasm responds to subcutaneous epinephrine or terbutaline
Where does asthma result in airflow obstruction?
- IN the tracheobronchial tree
What are the major childhood triggers of asthma?
-Viral infections and allergens
What may the physical exam of an asthmatic reveal?
- Wheezing, SOB, dyspnea, cough, increased sputum production and chest tightness
- Increased expiratory phase, tachypnea, cyanosis, tachycardia, use of accessory respiratory muscles
What are the treatments for asthma?
- Beta2 adrenergic agonists
- INhaled corticosteroids
- Leukotriene modifiers
- Mast cell stabilizers
- Systemic corticosteroids
What is the mainstay to acute symptomatic relief of asthma?
- Beta 2 adrenergic agonist (albuterol) => works rapidly to relax bronchial smooth muscle and reduces release of mast cell mediators and increases mucociliary clearance
What is the use of long acting beta2 adrenergic agonists in the treatment of asthma?
-Long acting beta 2 adrenergic agonists are effective at reducing the frequency of exacerbation in persistent asthma
What is the primary treatment of persistent asthma?
- Daily use of inhaled corticosteroids or leukotriene inhibitors are the tx for persistent asthma
- Reduces the production of inflammatory mediators and reduce vascular permeability
*NOT used for acute attacks
What organisms commonly cause conjunctivitis?
- Staphylococcus, Streptococcus, Haemophilus, Moraxella, and Pseudomonas
How long does conjunctivitis generally last?
- Self limiting 10-14 days
What abx is generally indicated in conjunctivitis?
- Sulfonamide will clear conjunctivitis in 2-3 days
What type of eye infection is highly contagious and spread by person to person and fomites?
- Keratoconjunctivitis (pink eye)
What is the most common cause of keratoconjunctivitis?
- Adenovirus => associated with pharyngitis, fever, malaise, and preauricular lymphadenopathy
- Usually lasts 2 weeks
What is the treatment for keratoconjunctivitis?
- Local sulfonamide therapy may prevent secondary bacterial infection
- Hot compress
- Weak topical steroids treat corneal infiltrates
