Cutaneous adverse drug reactions (CADR), also known as toxidermia, are skin manifestations resulting from systemic drug administration. These reactions range from mild erythematous skin lesions to much more severe reactions such as Lyell's syndrome.

In neurology, psychiatry, and neurosurgery, several human leukocyte antigen (HLA) alleles have been reportedly associated with cutaneous adverse drug reactions (cADRs) induced by antiepileptic drugs, which significantly carry the risk of developing cADRs. Prior to using antiepileptic drugs such as carbamazepine and lamotrigine, which are prone to cause severe cADRs, preemptive HLA genetic testing and therapeutic interventions such as drug selection and dosage adjustment based on the results of the tests can reduce the incidence of cADRs in the population before the initiation of treatment ¹⁾.