Which of the following is a common symptom of scalp ringworm?

A common symptom of scalp ringworm is indeed itchy patches of hair loss. Scalp ringworm, caused by fungal infection, leads to the development of round, scaly patches on the scalp that can become inflamed and itchy. As the infection progresses, it often results in hair falling out in those affected areas, creating noticeable bald spots on the scalp. This can cause significant discomfort due to the itchiness associated with the inflammation and irritation.

While painful scalp inflammation can occur, it is not as characteristic of scalp ringworm as the itchy patches; therefore, it is less indicative of this specific condition. Excessive dandruff may occur for various reasons but is not a direct symptom of scalp ringworm. Thickened hair strands are not symptomatic of scalp ringworm, as the disease typically leads to hair loss rather than changes in hair structure. Thus, the presence of itchy patches of hair loss is the most defining symptom of scalp ringworm, making it the correct response.