Medically reviewed by Jurairat J. Molina, MD A circular rash is commonly caused by a fungal infection called ringworm.

Before the onset of arthritis, some of the children had developed strange circular rashes where they had been bitten by ticks. Lyme disease has since become the most common tick-borne infection in ...

A common symptom of Lyme disease is a bullseye-shaped rash. However, many other conditions may cause a similar rash, including ringworm, fixed drug reactions, and allergic reactions to insect bites.

Spider mites appear as rashes caused by issues with the skin ... a rash with a great ability to spread through the skin, is a hallmark of Lyme disease, a serious bacterial disease.