The aim of the paper is to present and compare the clinical manifestations and results of treating two cases of Stevens‑Johnson syndrome (SJS) and associated mucositis as well as highlighting their most typical clinical features. SJS is the most serious cutaneous adverse drug reaction, usually including oral and ocular involvement, and there is a group of medicines that can cause SJS. Severe mucositis is usually preceded by a painful generalized erythematous vesiculobullous rash and mucosal involvement may extend to the oropharynx, larynx, nasal cavity and respiratory tract. Our cases demonstrated typical lesion development and progression. Mucositis may restrict mouth opening and cause difficulty with eating and speaking. SJS can cause severe, generalized inflammation and multi‑organ failure and is characterized by painful mucosal erythema with subsequent blistering and ulceration. In the cases presented here corticosteroids, antihistamines, anti‑viral drugs, antibiotics and antifungal drugs were applied.

Key words: Stevens‑Johnson syndrome, mucositis, adverse drug reactions.