<prompt> Incubation period of diphtheria:2-3 days5-7 days14-15 days21 days  <response>: Ans. a 2-3 daysRef: Harrisons 18th ed. Ch 138Harrisons states: The incubation period for respiratory diphtheria is 2-5 days; however, disease can develop as long as 10 days after exposureTypes of Diphtheria Infections are1. Faucial tonsillar pharyngeal- Commonest type, grey with white pseudomembrane and cervical lymphade- nopathy bull neck toxemia2. Laryngeal - Most severe form3. Nasal - Mildest form4. Cutaneous form - Only non toxigenic strain, punched- out ulcer5. Other form - Conjuctival, otic, genital 