Myringitis bullosa is caused by -
Myringitis bullosa hemorrhagica is a painful condition.
It is characterized by formation of hemorrhagic blebs on tympanic membrane and deep meatus. It is probably caused by virus or mycoplasma pneumoniae
(Dhingra 6/e, p 62) but according to Turner 10/e p 323
Common causes of otitis externa -
Fungus
Bacteria
Virus