Definitions Flashcards
Coryza (Common Cold)
Acute viral infection of the nasal passages; highly infectious due to rhinoviruses, coronaviruses and adenoviruses. Spread via droplets, facilitated by overcrowding and poor ventilation.
Sinusitis
Bacterial/fungal infection of paranasal sinuses, usually preceded by coryza. Can occur with asthma.
Rhinitis
Sneezing attacks, nasal blockage/discharge occurring >1hr on most days. Seasonal/Intermittent = limited period of the year; “hay-fever” but not restricted to grass pollen.
Pharyngitis
Endemic adenovirus infection, causing reddened oropharynx and soft palate and inflamed tonsils.
Acute Laryngotracheobronchitis
Occasional complication of URTIs, particularly those caused by parainfluenza viruses and measles. Most severe in children < 3yrs. Inflammatory oedema usually present which can spread to vocal cords.
Acute Epiglottitis
Life-threatening airway obstruction in children aged 2-7yrs caused by H. influenzae.
Influenza
Influenza A (pandemics) and Influenza B (localised outbreaks) incubate within 3 days. Not a cold!
Acute Bronchitis
“Cold which goes to the chest” – acute infection of bronchi causing them to become inflamed. Usually arises from Strep. pneumoniae/H. influenzae infections, or in people with COPD.
Pneumonia
Acute infection of the lungs causing inflammation. Community, Hospital and Immunocompromised acquired pneumonia. Main causes: Strep. pneumoniae, H. influenzae, Staph. aureus, Influenza A. Atypical causes: Mycoplasma, Legionella, Chlamydophila pneumoniae/psittaci, coxiella burnetti.
COPD (Chronic Obstructive Pulmonary Disease)
Encompasses 2 main clinical syndromes: chronic bronchitis and emphysema. Characterised by airflow obstruction that is mostly irreversible
Asthma
Chronic inflammatory condition where reversible obstruction of the airways occurs. Airflow limitation -> airway hyper-responsiveness -> bronchial inflammation.
Obstructive Sleep Apnoea
Airway becomes closed during sleep; muscles hypotonic during sleep and thus do not open airway. Partial occlusion results in snoring; complete occlusion results in apnoea (cessation of breathing).
Bronchiectasis
Abnormal permanent dilatation of airways, resulting inflammation and thickening of walls. Mucociliary transport mechanism is impaired and thus recurrent bacterial infections ensue. Cystic fibrosis = most common cause.
Lung Abscess
Localised suppuration assoc. with cavity formation on CXR/CT
Cystic Fibrosis
Autosomal recessive disorder in which there is a defect in the CFTR gene, a critical chloride channel. Failed opening of Cl channel -> ↑cAMP, resulting in ↓Cl and ↑Na -> ↑viscosity of airway secretions.
Tuberculosis
Airborne infection spread by droplets by Mycobacterium species. Affects 1/3 of population. Caseating granulomatous inflammation (necrotic centre; surrounded by epitheloid cells and Langhan’s giant cells; formation of Ghon focus/complex). Primary=first infection. Latent=asymptomatic, smear –ve.
Sarcoidosis
Multisystem non-caseating granulomatous Type IV hypersensitivity disorder of unknown aetiology.
Wegener’s Granulomatosis
Granulomatous disease predominantly affecting small arteries. Lesions in URT, lungs, kidney.
Churg-Strauss Syndrome
Eosinophilic infiltration with high blood eosinophil count, vasculitis of small arteries and veins. Predominately affects 40 year old males.
Systemic Lupus Erythematosis
Chronic type III hypersensitivity disease that causes inflammation in various parts of body.
Idiopathic Pulmonary Fibrosis
Patchy scarring of lung with collagen deposition and honeycombing. Late onset. Commoner in males.
Extrinsic Allergic Alveolitis (Hypersensitivity Pneumonitis)
Widespread diffuse inflammatory reaction in small airways and alveoli due to inhalation of foreign antigens, usually from animals. Cigarette smokers actually have decreased risk. Type III hypersensitivity.
Coal-Worker’s Pneumoconiosis
Dust particles typically 2-5 micrometres in diameter are retained in small airways and alveoli. Simple Pneumoconiosis more common form; refers to deposition of coal dust in lung. Symptoms usually COPD-related. CXR fine micro-nodular shadowing. Progressive Massive Fibrosis round fibrotic masses several cm in diameter develop in upper lobes -> apical destruction of lung. Necrotic central cavities.
Asbestosis
Fibrosis causes by asbestos dust exposure.
