It can be distressing to wake up with a mysterious swollen red rash on your ankle. Could that rash be an insect bite? And what kind of bug bit you? The answers aren't so easy to figure out.

A venomous spider bite (like this brown recluse bite) can cause a red or purplish rash radiating from the site of the bite. There are only a few species of spiders in the U.S. that can bite humans.

Nummular eczema, also called discoid eczema, is a type of eczema rash that shows up in a distinctive round pattern. The rashes may be itchy, red and raised ovals, the AAD says, and there may be ...

Here’s how to tell the difference between mosquitoes, chiggers and no-see-ums by their bites and how to treat and prevent them.

Delayed anaphylaxis to red meat masquerading as idiopathic anaphylaxis. J Allergy Clin Immunol Pract. 2014;2 (3):259-265. Wolver SE, Sun DR, Commins SP, Schwartz LB.

Of the malar rash causes, the most common is rosacea, a skin condition that is not connected with a systemic disease. A rash from rosacea is red with small bumps and tiny broken blood vessels. It ...

A venomous spider bite (like this brown recluse bite) can cause a red or purplish rash radiating from the site of the bite. There are only a few species of spiders in the U.S. that can bite humans.

A 38-year-old man presents to an otolaryngology clinic with itchy eyes, periorbital swelling, and an itchy red rash on his face and arms.