Toxic Epidermal Necrolysis Due to Concomitant Use of Lamotrigine and Valproic Acid
A 26 year old female was under treatment with valproic acid 750 mg/day, propranolol 10 mg/day, clomipramine 10 mg/day, and risperidone 2 mg/day for bipolar mood disorder and obsessive compulsive disorder since two years. Four weeks prior to presentation, she had been initiated on lamotrigine at 25 mg/day, which was rapidly increased to 50 mg BD over 2 weeks and 100 mg BD over another 2 weeks, at which time she developed skin rash and oral erosions. Examination revealed a rash typical of toxic epidermal necrolysis with erythematous macules, papules, flaccid blisters, targetoid lesions, and erosions over face, trunk and palms involving around 30% of body surface area []. Nikolsky's sign was positive. Genital and oral erosions with hemorrhagic crusting over lips and severe conjunctival congestion were observed. Systemic examination was unremarkable. A causality assessment of this adverse event revealed a probable association between lamotrigine and toxic epidermal necrolysis based on the Naranjo probability scale.[] Blood counts and basic biochemistry were normal. Lamotrigine and other drugs, except valproic acid, were stopped. She was given prednisolone 40 mg/day, in addition to supportive care. Prednisolone was tapered gradually, and the patient made an uneventful recovery and was discharged.