2021 Volume 20 Issue 2 Pages 122-127
Methotrexate (MTX), a common anti-rheumatic drug, became available for psoriasis treatment in November 2018 in Japan, and use by dermatologists is expected to increase. However, MTX is associated with a high frequency of adverse effects and requires careful administration. We report a case of agranulocytosis induced by methotrexate, which was diagnosed based on concurrent herpetic mucositis and herpes zoster. The patient, an 82-year-old female, received MTX for polymyalgia rheumatica and was hospitalized for herpes zoster on the left lower limb and an aphthous oral ulcer. After admission, MTX was discontinued due to agranulocytosis, and she was treated using folic acid,acyclovir, and granulocyte colony-stimulating factor. All symptoms improved as a result of these treatments. Biopsy of the oral mucosa and viral antibody tests demonstrated that the aphthous ulcer was due to HSV-2 infection. MTX use is associated with many side effects ; therefore,dermatologists should be familiar with them and their treatment methods. If stomatitis occurs during MTX administration, the possibility of HSV infection should be considered. Skin Research, 20 : 122-127, 2021
