Respiratory Diseases,第一课件网站,General Introduction,Respiratory disorders important as They account for 50 % of consultations with general practitioners for acute illness in young children and a third of consultations in older children Respiratory illness leads to 20-35 % of acute paediatric admissions to hospital, some of which are life-threatening Asthma is the most common chronic illness of childhood in the world,Acute Upper Respiratory Infection (AURI),Introduction,AURIs are the most frequently occurring illness in children. On average, children acquire three to eight AURIs every year. AURIs are generally caused by the viruses. There are little difference in the incidence of colds by sex, race, or geograhpic region. Environmental factors that increase the likelihood of acquiring cold include attendance at child care facilities, smoking, passive exposure to smoke, low income, crowding and psychologic stress.,Etiology,Viruses Cold viruses may be transmitted by three routes: Large-particle droplets, which can travel a short distance to directly inoculate another person Small-particle aerosols, which can travel longer distances and deposit directly in alveoli of other individuals Secretion, which are transmitted by direct physical contact,Etiology,Common viruses that usually cause common colds Rhinoviruses Parainfluenza or influenza viruses Respiratory Syncytial Virus (RSV) Coronaviruses Adenovirus Enteroviruses Coxsackie Virus and ECHO Virus Reoviruses,Etiology,The common cold has over 200 known viral causes: 30% are rhinoviruses. 40% are unknown. 15% are influenza or parainfluenza viruses. 10% are coronaviruses.(20% in adult.) 5% are enteroviruses.,Etiology,Parainfluenza viruses (types 14) often produce lower respiratory disease but, particularly in reinfections, the symptoms may present as uncomplicated AURIs. RSV often begins in infants as a AURI but spreads to the lower respiratory tract.,Etiology,Bacteria A bacteral infection is secondary. The most common bacteria: Streptococcus hemolyticus Influenza Bacillus Streptococcus Pneumoniae Mycoplasma Pneumoniae,Etiology,Other causes Characteristic of respiratory anatomy and physiology in children Characteristic of respiratory immunity in children Body states:Deficiency of vitamins and trace elements malnutrition Environmental factors,Pathogenesis,The offending virus invades the epithelial cells of URT. Inflammatory mediators are released. They alter the vascular permeability and cause tissue edema and stuffiness. Stimulation of cholinergic nerves in the nose and URT leads to increased mucus production (rhinorrhea) and occasionally to bronchocontriction Injury to cilia in the nasal epithelial cells may decrease ciliary function and impair clearance of nasal secretions.,Clinical Manifestations,Symptoms of Respiratory System Nasal obstruction Rhinorrhea Sneezing Coughing Pharyngodynia,Clinical Manifestation,General Symptoms Sudden onset Anorexia Fever Vomiting Diarrhea Restlessness, Convulsion Abdominal pain,第一课件网站 www.wenku188.com,Clinical Manifestations,Signs Congestion of throat Swelling of tonsil Submaxillary lymphadenopathy and cervical lymphadenopathy Skin rash,Clinical Manifestations,Symptoms of older children with URIs The patients usually experiences a sudden onset of clear or mucoid rinorrhea, nasal congestion, and fever. Mild sore throat, cough, sneezing, and eye irritation may develop. Headache, malaise, myalgia, and decreased appetite usually occur. The nose, throat, and tympanic membrane can appear red and inflamed. Most systemic symptoms subside within 57 days.,Clinical Manifestations,Infants with URIs Infants have a more general presentation. High-grade fever Irritable and restless Feeding and sleeping difficult Vomiting and diarrhea,Specific Types of URIs,Herpangina Herpangina is caused by coxsackie A group viruses. Herpangina is characterized by an acute onset of fever and oropharyngeal vesicles ( 3-4mm in size) and ulcers surrounded by an ery, and sometimes the characteristic lesions are found on the soft palate and uvula. Dysphagia , vomiting , and anorexia also occur. Symptoms disappear in 1 week.,Specific Types of URIs,Pharyngo-conjunctival fever This disorder is caused by type 3 or 7 adenovirus. Pharyngitis, conjunctivitis, fever and cervical lymphadenopathy are the main findings. Symptoms disappear in 1 2 weeks.,Complications,Acute otitis media Paranasal sinusitis Neck lymphrnoditis Retropharyngeal abscess Laryngitis Lower respiratory tract disease Acute glomerulonephritis and rheumatic fever,Laboratory Test,White cell count The viral infections is normal to low. The bacterial infections or viral-bacterial infection is high. Laboratory diagnosis of viral infections Antigen or nucleic acid detection Serologic testing Isolation of viruses by culture of the throat or nasopharynx Use of monoclonal antibodies Polymerase chain reaction (PCR),Diagnosis and Differential Diagnosis,Diagnosis According to symptoms and signs, AURIs are