This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
An unimmunized child is brought to you with a history of UI. On examination you find signs suggestive of diphtheria. Which type of diphtheria would suggest the worst prognosis? 
Select and explain. 
A. Tonsillopharyngeal, B. Laryngeal, C. Nasal, D. Cutaneous
B: Laryngeal
Answer: B: Laryngeal 
Explanation: Tonsillopharyngeal type of diphtheria is the commonest type of diphtheria infection. Here there is a small chance for bullneck and toxemia. In case of laryngeal diphtheria there is a real danger of asphyxia and urgent tracheostomy may be required to save the patient. Hence it is the most severe form of the disease and has got the worst prognosis. Nasal diphtheria is the mildest form of respiratory diphtheria. Cutaneous diphtheria is caused by non toxigenic strains. Ref: Textbook of Microbiology by Ananthanarayan, Edition 6, Page 217; Harrison, Edition 17, Page 891, 892