All of the following cause a grey-white membrane in the throat except -
Causes of the membrane in the throat (Differential diagnosis of the membrane over the tonsil) 

Pyogenic membranous tonsillitis
Infectious mononucleosis
Traumatic ulcers
Vincent's angina
Agranulocytosis
Adenovirus pharyngitis
Candidal infection of tonsil
Leukemia
Diphtheria
Aphthous ulcers
Streptococcal tonsillitis
Diphtheria
Ludwig's angina
Adenovirus pharyngitis