Onychomycosis is caused most commonly by Trichophyton rubrum or T. mentagrophytes. About 10% of all persons worldwide and 40% of those ≥60 years old are believed to have the disease. Risk factors include older age, diabetes, poor peripheral circulation, smoking, HIV infection, psoriasis, and immunosuppression. Left untreated, onychomycosis can cause nail plate destruction, ingrown nails, and (particularly in patients with diabetes) secondary infections. Guidelines on treatment of onychomycosis have been published.

Diet, exercise, and weight loss can improve glycemic control, but almost all patients with type 2 diabetes require antihyperglycemic drug therapy. Treating to a target A1C of <7% while minimizing hypoglycemia is recommended to prevent microvascular complications of diabetes (retinopathy, nephropathy, and neuropathy). An A1C target of <8% may be appropriate for some older patients.

The goal of drug therapy for type 2 diabetes is to achieve and maintain a near-normal glycated hemoglobin (A1C) concentration without inducing hypoglycemia; for most patients, the target A1C is <7%. Metformin is the preferred first-line treatment, but most patients with type 2 diabetes eventually require multidrug therapy and/or insulin to achieve glycemic control.

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.

About 50% of the world’s population is infected with Helicobacter pylori. These gastric bacteria can cause chronic inflammation and have been associated with development of gastritis, peptic ulcer disease, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Eradication of H. pylori can promote gastric healing, prevent recurrence of duodenal and gastric ulcers, and reduce the incidence of gastric cancer. Guidelines for treatment of H. pylori infection were updated recently.

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.

Cognitive behavioral therapy for insomnia (CBT-I) is recommended for initial treatment of chronic insomnia. CBT-I includes stimulus control, sleep education and hygiene, sleep restriction, relaxation training, and cognitive therapy. When CBT-I alone is not effective, pharmacologic treatment should be added.

Annual vaccination in the US against influenza A and B viruses is recommended for everyone ≥6 months old without a contraindication. Influenza vaccines available in the US for the 2024-2025 season are listed in Table 2.

Drugs for gout are used to reduce the pain and inflammation of acute flares, decrease the frequency of exacerbations, and lower serum urate levels to prevent recurrent flares, development of tophi, and joint damage.

Many commonly used drugs can interfere with sexual function in both men and women, causing loss of libido, interfering with erection or ejaculation in men, and delaying or preventing orgasm in women. Drug-related effects on sexual function may be difficult to distinguish from the effects of depression or disease, but most are reversible when drug use is stopped and sometimes when dosage is decreased. Since many patients are reluctant to talk about sexual difficulties, physicians may wish to ask about the possibility of drug-induced sexual dysfunction, particularly when they have...