Abstracts

Rationale: Lamotrigine (LTG)-associated skin rash mainly occur as delayed hypersensitivity reaction. In rare cases it is accompanied by severe clinical condition. Predictors of LTG-induced rash remain unclear. Methods: A retrospective study of the incidence of LTG-induced skin adverse reaction in children with epilepsy was carried out. In a period from January 2000 to December 2007 a total of 512 out-patients with symptomatic (323) or cryptogenic/idiopathic (189) etiology, were treated with either add-on LTG (403) or in monotherapy (108 patients) with mean age of 13.6. Results: Rash occurred in 21 (4.1%) patients (9 male, 12 female) aged from 5 to 17 years (mean 11.5). Symptomatic etiology was significantly more often associated with rash (15; 4.6%) than idiopathic one (6; 3.2%). Skin lesions appeared with add-on LTG in 16 patients with intractable epilepsy (valproate-9, carbamazepine-3, oxcarbazepine-1, topiramate-1, primidone-2) while in 5 children with LTG given in initial monotherapy. Moderate diffuse macular-papular or erythematous rash appeared in 14 patients, while severe urticarial skin eruption was observed in 6 patients. Four of them required hospitalization. One case of mild Stevens-Johnson syndrome occurred. No patients with toxic epidermal necrolysis were noted. Rash occurred within 2 to 3 weeks (x-16 days) after LTH starting in 19 children. In two patients the skin eruption appeared during the first week of therapy. Higher initial LTG dose or dose escalation faster than recommended, were recognized in 3 patients. Seven (33.3%) patients with LTG induced rash had previous history of hypersensitivity reaction to AEDs, antibiotics or antipyretics when compared with 23(4.5%) of total number of children. LTG was discontinued in all but one patient, with complete recovery. Seizures increased in 5 patients during rash or after the LTG withdrawal. Conclusions: Symptomatic seizure etiology, intractable epilepsy, valproate co-medication, medical history of rash attributed to other, previously used AED/medications are identified as factors contributing to the high risk of LTG-induced skin adverse reactions. No gender, age and titration rate of LTG were recognized as predictors for LTG associated rash.