Otolaryngologic manifestations of phenytoin toxicity

DPH may result in protean head and neck manifestations (Table 1). In some cases these effects are dose related and in others they appear to be idiosyncratic; some occur only at toxic levels (Table 2). Many of the conditions are reversible and withdrawal of DPH or re-establishment of therapeutic levels is the only treatment necessary. Failure to recognize this fact can result in expensive workups or, worse, in aggressive treatment, both of which are unnecessary. The otolaryngologist should therefore be aware of these conditions and consider them in the differential diagnosis.