Oxcarbazepine-Induced Cutaneous Reaction in a Female of Mexican Ancestry

Objectives: To report an oxcarbazepine (OXC)-induced cutaneous reaction in a female of Mexican ancestry. Case Summary: A 60-year-old female of Mexican ancestry presented to clinic with a diffuse morbilliform rash, with erythema and eruptions of papules/pustules concentrated on her neck and torso. The rash appeared 1 week following the initiation of OXC for trigeminal neuralgia. Initially, the correlation between the reaction and initiation of OXC was not recognized by the provider. OXC was continued for a total of 4 weeks and several medical encounters transpired in the interim. Supportive therapy, in the form of oral antihistamines and oral/topical corticosteroids, failed to resolve the rash. A clinical pharmacist prompted the discontinuation of OXC due to suspicion that it incited the adverse reaction. Oral corticosteroid therapy was initiated and tapered over 2 weeks, with rash dissipation occurring in 1 month. Discussion: The association of OXC with the cutaneous eruption was classified as "probable" based on the Naranjo Scale. While financial resources were not available to perform genetic testing, it may be possible that the genetic status of this patient lent itself to greater potential for cutaneous reactions with OXC. Further research is needed to determine whether pharmacogenetic variables affiliated with pre-Columbian lineage may predispose individuals to specific adverse drug reactions. Conclusion: As regional genotypes disperse globally, it is imperative that clinicians are cognizant of risks regarding genetically implicated adverse drug reactions. While information is limited for certain ethnicities, it is essential that providers diligently monitor all populations for reactions characteristic to specific medications.