Rationale: Adult-onset Still disease (AOSD) is a rare inflammatory disease of unknown etiology. AOSD is common in young or middle-aged adults; however, in recent years, there have been increasing reports of elderly AOSD. Differentiating AOSD from diseases such as infections and malignancies is difficult. Moreover, rare fulminant AOSD cases with resistance to corticosteroids and immunosuppressive drugs have been reported.Patient concerns: An 80-year-old woman presented with flaccid fever, generalized arthralgia, and erythema of the anterior chest for 2 weeks. On day 5 of hospitalization, the patient developed pleural effusion with hypoxemia and her vital signs indicated rapid progression to shock. During the clinical course, the levels of inflammatory markers, including maximum level of ferritin and white blood cells (WBCs) were elevated (252,796 ng/mL and 86,500/μV, respectively) with disseminated intravascular coagulation syndrome (DIC) and macrophage activation syndrome (MAS). Diagnosis:The patient was diagnosed with elderly AOSD as per the Yamaguchi criteria for AOSD. The state of disease was extremely severe with rapid progression and was, thus, categorized as a fulminant form of elderly AOSD. Interventions:The patient was treated with prednisolone (PSL) pulse therapy (1000 mg/d) twice and plasma exchange in the intensive care unit for the primary disease and shock. Although she recovered from shock, she developed DIC and MAS. Methotrexate (MTX; 10 mg/d) improved the DIC and MAS. However, severe pleuritis recurred and the patient developed pericarditis; her primary disease was poorly controlled. Finally, tocilizumab (TCZ) was introduced using interleukin-18 (IL-18) as a surrogate marker. The IL-18 level was measured repeatedly following admission, with the peak level (170,000 pg/mL) recorded on the 75th day of hospitalization, immediately prior to introducing TCZ.Outcomes: The combined use of MTX, TCZ, and PSL was effective in suppressing elderly AOSD, which was unsuccessfully controlled with MTX and PSL. Frequent monitoring of IL-18 levels proved useful for differentiating elderly AOSD from other diseases.Lessons: A fulminant form of elderly AOSD was treated with a combination of MTX, TCZ, and PSL. Repeated monitoring of IL-18 levels can be useful for decision-making in treating elderly AOSD.

We present a case of a 58-year-old woman with anorexia nervosa and a sacral decubitus ulcer who developed hypothyroidism because of an iodine-containing ointment. Considering the absence of autoimmune thyroid diseases, the development of hypothyroidism after the use of an iodine-containing ointment, and the recovery of thyroid function after the discontinuation of the ointment, we presumed that her hypothyroidism was induced by the iodine-containing ointment. Although the hypothyroidism improved after discontinuing the iodine-containing ointment, she developed aspiration pneumonia and required long-term hospitalization. Many patients with autoimmune thyroid diseases develop hypothyroidism after excessive iodine intake. However, anorexia nervosa may have exacerbated the iodine-induced hypothyroidism in our patient. To the best of our knowledge, no previous study has reported a case of hypothyroidism caused by iodine-containing ointment in a patient with anorexia nervosa. Hence, physicians must pay careful attention to a patient's background factors to ensure the early diagnosis of hypothyroidism due to iodine-containing ointments.

Pneumatosis cystoides intestinalis is an uncommon disease that rarely causes intussusception. We report the case of a 16‐year‐old male patient with intermittent abdominal pain who was diagnosed with intussusception. The patient had no history of raw food ingestion, fever, diarrhea, or hematochezia. Computed tomography revealed intussusception characterized by a crab‐finger appearance, and pneumatosis cystoides intestinalis was diagnosed by colonoscopy. Treatment with hyperbaric enema and low‐flow oxygen therapy resulted in a prominent improvement of the lesion. No recurrence was observed for > 1 year. Intermittent abdominal pain without diarrhea or hematochezia in male adolescents may represent pneumatosis cystoid‐related intussusception, and the addition of low‐flow oxygen therapy may help avoid surgery.