INFECTIOUS DISEASES AND INFECTIONS 1 DIPHTHERIA

INFECTIOUS DISEASES AND INFECTIONS 1 DIPHTHERIA Epidemiology - Age - Maximum incidence between 2-5 years Mode of spread - Droplet infection due to contact with person with active disease or more often with a carrier of virulent organisms Chronic sinusitis and diseased tonsils important predisposing factors Sub types of C diphtheriae - Three strains gravis, intermediate, and mitis usually related to the clinical severity of the disease, the other factors being host-resistance, site of infection and length of time elapsing before starting treatment Incubation period - 2 to G days Clinical types - 1 RESPIRATORY GROUP - includes majority Nasal diphtheria - Unilateral or bilateral nasal discharge, at first serous and often blood stained, later thick, mucopurulent and foul smelling Thick membrane may be visible on the mucosa of the anterior part of nasal septum Redness, excoriation, small follicular spots or pustules commonly present on upper lip round the nose Constitutional symptoms slight or absent Faucial diphtheria - Mild - Reddening of one or both tonsils with small membrane formation on one tonsil or in a tonsillar fossa Moderate - Membrane on both tonsils confined to tonsillar fossa Localised tonsillar lymphnode enlargement Severe - Spread of membrane to one of the faucial pillars and thence to palate on one side. The membrane has a characteristic oedematous margin and is spreading Tonsillar nodes enlarged with some oedema of surrounding tissues Very severe - Rapidly spreading filmy membrane on soft palate and roof of mouth with gross oedema of faucial and palatal tissue The membrane may be hemorrhagic. Gross swelling of neck (bull neck). Temperature in moderate to moderately severe cases seldom more than 38°C. Laryngeal diphtheria - More common in infants. Membrane involves larynx and also spreads to trachea and bronchi Initial symptoms are hoarseness, brassy cough and noisy breathing. Progressive laryngeal obstruction produces inspiratory stridor. Lower intercostal spaces are sucked in as not enough air flows in to fill the lungs If not relieved child dies of hypoxia 2 NON-RESPIRATORY GROUP - include vulva, vagina, umbilical cord, conjunctiva, auditory meatus, tongue and oesophagus Glans or coronal sulcus of penis after circumcision in infants Cutaneous diphtheria may present as a chronic ulcer or a persistent shallow ulcer with punched out areas. Diagnosis - Throat or laryngeal swab for smear (unreliable), or culture on glycerol-tellurite culture plate and Loeffler slope Complications - Aspiration of membrane can cause respiratory obstruction .1. Cardiovascular COMPLICATION Timing CLINICAL FEATURES Myocarditis Circulatory failure Acute onset Tough, ashy-grey uniform deposit Soft, yellowish white deposits in spots or patches with intervening areas of redness. Membrane very adherent, bleeding points Membrane easily removed leaving smooth when torn off surface. Pillars of fauces and uvula may be involved Deposit limited to tonsils Fever usually slight Fever high Cervical glandular enlargement rare. Cervical glands commonly enlarged 2 Moniliasis - Most common in infants, patches of soft deposit of fungus on buccal mucosa and tonsils. Exudate white and characteristically arranged as small linear membranes. Moniiia albicans will be seen on smear 3 Vincent's angina - Gingivitis with ulceration, no toxemia, marked foetor of breath, presence of fusiform bacillus and spirillum 4 Infectious mononucleosis - occurs usually in older children Exudate as a rule remains white Glands in neck enlarge but remain discrete Patient usually less ill .5 Agranulocytosis -