The identification of EM-associated conditions is crucial for specific treatments, alone or in addition to corticosteroids: in hypersensitivity or allergic EM, potential causative factors must be identified and eliminated; targeted antimicrobial therapy is necessary for EM associated with helminthic infections (i.e., albendazole); tyrosine kinase inhibitors could be used in myeloproliferative disorders with eosinophilia characterized by PDGFRA/B-rearrangement; EGPA-related EM may benefit from cyclophosphamide therapy [16]. Here, PDGFRA is linked to erythema multiforme.