Possible ringworm infection symptoms include red patches resembling a ring with well-defined edges, itching, blistering and oozing, according to MedlinePlus. Ringworm affecting the scalp often causes bald patches. If ringworm affects the nails, the nails may appear thick or discolored.
Ringworm is not caused by a worm but rather by a fungus. The fungus is contagious and spreads by direct contact or by sharing personal items that have come into contact with the infection, states WebMD. Jock itch is a form of ringworm found in the groin area.
Ringworm often starts as a scaly, flat, red, itchy patch of skin, says Mayo Clinic. The patch gradually grows into the hallmark ring shape that often occurs with the ringworm infection. The border often becomes raised, while the inside may remain flat without as much redness. The outer edges are not always a perfect circle. The border may appear wavy or irregular. It is also possible to develop multiple rings that may or may not overlap.
The bald patches caused by ringworm on the scalp often feature hair broken off just above the scalp, explains Mayo Clinic. This broken hair looks like small dark dots. Other people notice patches of hair becoming brittle or fragile. The patches sometimes get larger and may include scaling, redness or graying. The scalp is often painful or tender.