After an adverse reaction, many patients never take penicillin again — even though they've never been formally tested by an allergist. But these patients may want to take another look.

In the fight against human immunodeficiency virus (HIV), one treatment may be safer than previously thought.

In the US, routine HPV vaccination is recommended for all girls before age 13. So why are so many still not getting vaccinated?

Anyone with Internet access can now track every US foodborne illness outbreak reported in the past 15 years.

Many parents know the human papillomavirus (HPV) vaccine can protect against cervical cancer. But new evidence suggests that some US teens are still not getting vaccinated.

Consumers, beware! Imported products marketed as "dietary supplements" or "herbal alternatives" to prescription drugs may do you more harm than good.

Antibiotic-resistant "superbugs" are here — and new evidence suggests that their numbers are rising.

The flu can be a major risk for elderly patients. But the type of flu vaccine these patients receive could lower that risk.

Hepatitis B infection can be a serious risk for patients with HIV. But there may be some good news on that front.

A new test for meningitis and encephalitis could bring the time needed for results down from three days to one hour.