LAUSR

may play an important role in MRH development via the IL6/JAK(1/2)/NFB ligand axis [4, 5]. JAK inhibitors may be an effective option for the treatment of MRH because they block this pathway. Tofacitinib and upadacitinib have been used to treat MRH, and the patients experienced considerable improvement of their skin lesions within eight weeks in both cases [6, 7]. A recent publication reported the successful treatment of one patient with progressive nodular histiocytosis with baricitinib [8]. Therefore, baricitinib should be considered a promising treatment option for MRH, although our results need to be confirmed in additional patients. Before using baricitinib, comprehensive tumour screening and JAK2 mutation testing should be performed, and baricitinib should be avoided if the result is positive [9].