Exacerbation of myasthenia gravis with voriconazole

Ocular Myasthenia Induced by Rivaroxaban in Patient with Deep Vein Thrombosis

The non-vitamin K antagonist oral anticoagulant rivaroxaban is indicated in prevention and treatment of venous thromboembolism (VTE). A 60-year-old male patient complained of bilateral ptosis after administration of rivaroxaban for deep vein thrombosis (DVT). Myasthenia gravis (MG) was confirmed by positive serum antiacetylcholine receptor antibody test. No mediastinal thymoma was found. The ocular myasthenia reversed after discontinuing rivaroxaban treatment. Nevertheless, ptosis recurred and chronic oral pyridostigmine bromide treatment was necessary. The mechanism of MG development by rivaroxaban therapy is not completely understood. The development of rivaroxaban-induced autoimmune disease could be based on cross-reactivity between antibodies against rivaroxaban-derived antigens or by T-cell activation. To our knowledge, this report of ocular myasthenia by rivaroxaban administration is the first in the literature. Despite the benefits of rivaroxaban, it is important to recognize unexpected immune-related adverse events.

Morphological and Molecular Characterization of Exophiala polymorpha sp. nov. Isolated from Sporotrichoid Lymphocutaneous Lesions in a Patient with Myasthenia Gravis

Exophiala species are capable of causing cutaneous and subcutaneous infections in immunocompromised patients. An Exophiala isolate was cultured from a biopsy specimen of a lesion on the forearm of a patient with myasthenia gravis. The patient also had lesions on the palm and distal aspects of the hand, which were successfully treated with a long-term course of itraconazole. A detailed morphological and molecular characterization of the isolate was undertaken. Phylogenetic analysis of the internal transcribed spacer region and portions of the β-tubulin and translation elongation factor 1-alpha genes indicated that the isolate was a novel species closely related to but genetically distinct from species within the Exophiala spinifera clade; the name Exophiala polymorpha sp. nov. is proposed. Morphologically, E. polymorpha most closely resembles E. xenobiotica but it differs in possessing phialides bearing prominent, wide collarettes, and it does not produce chlamydospores.