Drug Rash with Eosinophilia and Systemic Symptoms" (DRESS) syndrome is a severe adverse drug reaction. The drugs most often implicated are anti-convulsants, bupropion, sulfonamides, sulfasalazine, allopurinol, minocycline, abacavir and neviparine. There are also immune and infectious causes that can lead to DRESS syndrome. A 70-year-old female patient had undergone endovascular coil embolization for intracranial aneurysm and experienced a generalised seizure postoperatively. She had been given diphenylhidantoin (DPH). Six days after DPH therapy, the patient had complained of widespread skin rash. Although DPH was replaced with levetiracetam afterwards, the skin rash deteriorated, causing facial oedema and swelling of the tongue. She had severe facial oedema with swelling of the tongue, causing disturbance of breathing. On the second day in the critical care unit, the patient's breathing deteriorated, leading successively to intubation and mechanical ventilation. The patient's rash was still persistent and the results of a punch biopsy taken from the lesions revealed superficial perivascular dermatitis involving spongiotic eosinophils compatible with spongiotic drug eruption. As a result, it is important to realise that medications we use can be the cause of a range of reactions ranging from simple rash to life threatening syndromes.