Rare case of phenytoin induced acute generalized exanthematous pustulosis with cerebellar syndrome
An 18-year-old male was admitted to infectious disease ward for fever and generalized erythematous rash since one day. A diagnosis of viral exanthem was made. On detailed history taking patient was found to be a known case of seizure disorder on regular levetiracetam since three years. Patient gave past history of an allergic rash to phenytoin three years ago. Patient had received loading intravenous dose of phenytoin (1000 mg) one day prior to admission. On examination patient was febrile and was having facial edema [] with predominant involvement of lips. There was total sparing of oral mucosa. Patient had generalized erythematous macular rash along with multiple non follicular pustules more pronounced on chest [] and back [] but also involved the axilla [] and neck. There was no involvement of palm and soles. In addition, patient had cerebellar signs in the form of horizontal, up beating and down beating nystagmus along with bilateral swaying while walking suggestive of signs of acute phenytoin toxicity. Rest of general and systemic examination was unremarkable. In view of clinical presentation and history, diagnosis of acute drug reaction was kept and dermatologist opinion was taken. A provisional diagnosis of acute generalized exanthematouspustulosis was made and skin biopsy and gram stain of the pustule was done. His investigations revealed leucocytosis (TLC-11,500) and deranged kidney function test (Urea-55 mg/dl; Creatinine-2.2 mg/dl) with normal liver function test. Skin biopsy revealed spongiosis with dermal neutrophilic and eosinophilic infiltrate [] which are features of acute generalized exanthematous pustulosis. Gram staining of smear from the pustule showed no organism. Patient was treated with tapering doses 40 mg of oral corticosteroids along with antihistaminics. Patient responded dramatically with total subsidence of rash with desquamation [Figures and ]. Facial edema subsided completely. His cerebellar signs disappeared and kidney function test was normal within 15 days and patient was discharged with no sequelae.