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

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.

Lyme disease rashes usually appear within 1 to 4 weeks after the tick has bitten you, though it can take up to 3 months to appear. Not everyone who has Lyme disease gets a bull’s-eye rash ...

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 ...

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.