<prompt> The type of Diphtheria with highest moality is-PharyngealNasalLaryngealConjuntival  <response>: In laryngotracheal diphtheria if infection extends in to bronchial tree , it is the most severe form of disease. Prostration and dyspnoea occurs as a result of obstruction caused by membrane. This may cause suffocation if not treat properly with intubation or tracheostomy Reference : Park;s Textbook of preventive and social medicine, 24th edition.Pg no171 