Differential Diagnosis external otitis or furunculosis of external auditory meatus postauricular tenderness bullous myringitis: the earache may be intense but deafness only slight, the membrane may be obscured by a large haemorrhagic bleb or blebsDifferential Diagnosis  external otitis or furunculosis of external auditory meatus: postauricular tenderness.  bullous myringitis: the earache may be intense but deafness only slight, the membrane may be obscured by a large haemorrhagic bleb or blebs