Clostridioides (formerly Clostridium) difficile infection (CDI) is the most common infectious cause of healthcare-associated diarrhea in adults. Guidelines on management of CDI have recently been updated.

In overactive bladder, involuntary bladder contractions due to detrusor overactivity result in urinary urgency, frequency, nocturia, and incontinence. The prevalence of the disorder increases with age. Nonpharmacologic treatment, including bladder training, urge suppression, pelvic floor muscle exercises, constipation management, modification of fluid intake, and avoidance of dietary irritants such as alcohol and caffeine, should be tried first.

In June 2021, the FDA approved the IV amyloid beta-directed monoclonal antibody aducanumab (Aduhelm) for treatment of Alzheimer’s disease. The approval did not restrict use of the drug to patients with mild cognitive impairment or mild dementia, which was the population enrolled in the clinical trials. Now, Biogen, with the permission of the FDA, has made an addition to the labeling of the drug that says: Treatment with Aduhelm should be initiated in patients with mild cognitive impairment or mild dementia stage of disease, the population in which treatment was initiated in clinical...

Influenza is generally a self-limited illness, but pneumonia, respiratory failure, and death can occur, especially in persons at increased risk for influenza complications (see Table 1). Updated information on influenza activity and antiviral resistance is available from the CDC at cdc.gov/flu.

Annual vaccination against influenza A and B viruses is recommended in the US for everyone ≥6 months old without a contraindication. Influenza vaccines available in the US for the 2025-2026 season are listed in Table 2.

Excessive exposure to ultraviolet (UV) radiation can cause erythema, photoaging, and skin cancer. Sunscreens are widely used to reduce these risks, but questions remain about their effectiveness and safety. In 2021, the FDA proposed a rule that would require additional safety studies for some sunscreen active ingredients and mandate better UVA protection in sunscreen products.

An oral nonopioid analgesic is often sufficient for acute treatment of mild to moderate migraine pain without severe nausea or vomiting. A triptan is the drug of choice for treatment of moderate to severe migraine in most patients without vascular disease. Treatment of pain when it is still mild to moderate in intensity improves headache response and reduces the risk of recurrence.

The Advisory Committee on Immunization Practices (ACIP) recommends use of certain vaccines in adults residing in the US. Routine childhood immunization has reduced the overall incidence of some of these vaccine-preventable diseases, but many adults remain susceptible. Recommendations for vaccination against COVID-19, seasonal influenza, and monkeypox and vaccination of travelers have been reviewed separately.