Doctors emphasize that shape alone is not enough to make a diagnosis, but it can narrow down possibilities.
Fungal Infections: One of the Most Common Causes
One of the most frequent reasons for circular red patches is a superficial fungal infection, often called ringworm (despite having nothing to do with worms). These infections thrive in warm, moist areas of the body, such as the groin, buttocks, thighs, and under skin folds.
Typical signs include:
Red or pink circular patches
Slightly raised or scaly borders
Clearer skin in the center
Mild itching or irritation
Fungal rashes often spread slowly and may worsen if treated incorrectly with steroid creams instead of antifungal products.
When It’s Not a Fungus
Not all circular rashes are fungal. Doctors point out several other possibilities:
Eczema (nummular eczema)
This condition can cause coin-shaped red patches that are dry, itchy, and inflamed. Unlike fungal rashes, these usually lack a sharply defined border.
Psoriasis
Certain forms of psoriasis can create round, red plaques with silvery scaling. These patches are often chronic and may appear on multiple parts of the body.
