The aim of this case report is to highlight new possible treatment methods for concomitant juvenile idiopathic arthritis and multiple sclerosis in young patients. Promising results of using ofatumumab, secukinumab and dimethyl fumarate, both in the clinical case of a 22-year-old patient and mentioned literature, allows the belief that there is a chance for improving the quality of life of those who suffer from coexisting autoimmune diseases. However, it is crucial to perform further research in terms of the necessity and safety of the mentioned therapies, especially in the paediatric population, among whom there often exists difficulty in using treatment not registered for under-aged patients. Furthermore, the higher risk of side-effects caused by combined treatment of two autoimmune diseases should also be taken into consideration. juvenile idiopathic arthritis; autoimmune diseases; ofatumumab; dimethyl fumarate; multiple sclerosis; secucinumab