Psoriasis Archive

A lower-than-usual white blood cell count is often temporary, especially after illness. Find out what your number may mean and when retesting might be needed.

Several factors increase the risk for complications from COVID-19 or influenza and should prompt someone to request an antiviral medication as soon as possible, even if they have been vaccinated or have had the infections before. The risk factors are age (being 65 or older), an impaired immune system, and underlying conditions (especially heart or lung disease). Pregnant women also are at increased risk for severe influenza and COVID, and should consider taking an antiviral.

A positive TB skin test can raise questions about infection, exposure, and what happens next. Find out which follow-up steps may be needed.

Itchy, irritated skin can leave behind stubborn dark patches in unexpected places. Find out what may help restore your skin’s usual tone.

Chronic hives can be hard to control when testing does not reveal a cause. Explore possible triggers and treatments that may help bring relief.

A neck rash that stings and itches can have several possible triggers. The timing, recent exposures and other symptoms may help point to the cause.

Repeated underarm boils can have different causes and may need more than home care. Find out what symptoms matter and how doctors approach treatment.

Athlete’s foot causes itchy, scaly skin on the feet, and the fungus can sometimes spread to other vulnerable areas of the body too.

Discover what dark vertical streaks on fingernails might mean, from benign nail pigmentation to signs of a more serious skin cancer.

As of August 2026, sunscreens in the United States will be allowed to use an ingredient called bemotrizinol. It blocks both UVA and UVB rays and it doesn’t appear to be absorbed into the bloodstream, unlike many sunscreen chemicals.