Febrile rash diseases are sometimes infectious and require infection control intervention. Since November 2018, an outbreak of rubella in Japan has resulted in infectious disease physicians being consulted by outpatients with febrile rash or infection-suspected rash. We analyzed the epidemiology of our adult rash outpatients. Between November 2018 and April 2019, we summarized the medical chart information gathered during our consultations with patients who presented with a rash at the Chidoribashi General Hospital and Chiyo Clinic. Rubella and varicella cases were described separately in order to clarify the clinical characteristics. This study included 27 cases. The mean age ± standard deviation (SD) was 32.1 ± 13.6 years. The most common diagnoses were rubella and varicella (six cases each). Among the rubella cases, the mean age ± SD was 30. 5 ± 9. 7 years. Arthralgia, cervical lymphadenopathy, and conjunctivitis were common among these cases. The mean age ± SD for the varicella cases was 30.3 ± 6.9 years. It was remarkable that three of the six varicella cases were long-term foreign residents. Although the study period covered the duration of the rubella outbreak, infection control practitioners should remember that adult rash cases frequently require isolation precautions and are preventable with the use of vaccines. In addition, varicella vaccinations for Japanese adults and long-term foreign residents should rank in importance with vaccinations for rubella and measles, even in Local Japanese cities.

Abstract
　　The patient was a 71-year-old man with no subjective symptoms. While hospitalized under his previous doctor for gastric ulcer, soft-tissue shadows around the abdominal aorta were discovered by chance with abdominal computed tomography. The patient was referred to our department for further examination. He presented with high immunoglobulin G (IgG) and IgG4 levels, and computed tomography showed soft-tissue shadows around the abdominal aorta, atrophy of the pancreatic tail, and multiple enlarged lymph nodes, which suggested IgG4-related disease. However, he was also positive for antinuclear antibodies and anti-double-stranded DNA antibodies, and on admission exhibited hypocomplementemia and multiple pinpoint purpura on both lower legs. A skin biopsy of this area revealed signs of leukocytoclastic vasculitis, which suggested systemic lupus erythematosus accompanied by vasculitis. Differentiating these diseases was difficult, so a lymph node biopsy in the external iliac artery region was performed, based on which a final diagnosis of IgG4-related disease was made. He was given prednisolone starting at 0.6 mg/kg/day, which resulted in a positive course.