Delayed Stevens-Johnson Syndrome Secondary to the Use of Lamotrigine in Bipolar Mood Disorder.

Lamotrigine is a mood-stabilizing drug used in maintenance treatment of bipolar I disease. There are adverse effects with lamotrigine such as a headache, blurred vision, diplopia, somnolence, ataxia, dizziness, rash, Stevens-Johnson syndrome (SJS), and toxic epidermal necrolysis. SJS is a life-threatening, blistering mucocutaneous disease. SJS is characterized by the presence of flat, diffuse erythematous maculopapular rashes with the involvement of <10% of the body surface area. Standard trigger is drugs including anticonvulsants, antibiotics, and infection. We report a case where a patient developed SJS secondary to delayed-type hypersensitivity reaction after 6 months of the use of lamotrigine, while his initial response during the first 6 months did not show any sign of SJS.