Skin drug reactions are cutaneous rashes caused by drugs, through different pathogenic mechanisms that can be classified into two groups: immunologically mediated and non-immunologically mediated. In the first part of this chapter we are going to study the cutaneous reactions to aromatic antiepileptic drugs, namely phenytoin, and focusing attention towards potentially life-threatening drug reactions of an immune cause such as toxic epidermal necrolysis and hypersensitivity syndrome. Secondly we are going briefly summarize skin reactions to drugs usually dealt with in neurological diseases, following a classification based on the morphological aspects of the lesions present in each reaction.