eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2019-12-28 12 04 2123 2132 10.13005/bpj/1847 29797 article Sura Ali Ahmed Fuoad 1 Fadia Michel Kusairy 2 Walid Shabban Al-Sayed 3 Prabhu M. N. 4 Pooja Narain Adtani 5 Oral Medicine and Academic Associate Dean College of Dentistry/Gulf Medical University –Ajman, UAE Clinical lecturer and specialist, Thumbay hospital –Ajman, UAE Oral biology, head of basic dental science department,College of Dentistry/Gulf Medical University –Ajman, UAE Periodontology, College of Dentistry/Gulf Medical University –Ajman, UAE Oral pathology, College of Dentistry/Gulf Medical University –Ajman, UAE One of the commonly encountered lesions in oral cavity is oral ulceration.  They arise from various etiology, being associated with discomfort or pain, rarely results in complications and scarring. The nonspecific clinical presentation of oral ulceration in the oral cavity, will made their diagnosis crucial, however a detailed patient history, comprehensive clinical examination together with background knowledge of possible causes will lead to correct diagnosis and subsequent treatment, moreover distinguishing between erythema multiforme (EM) and herpes simples viral infection (HSV) when there is only oral involvement is of a great importance as the treatment of EM is contra indicated for HSV. https://biomedpharmajournal.org/vol12no4/erythema-multiforme-versus-herpes-simplex-virus-what-is-the-diagnosis-a-review-and-a-case-report/ Oral ulceration erythema multiforme (EM) herpes simplex viral infection (HSV) treatment