Hello,
This itchy patch can be due to hives or fungal infection like ringworm. Hives (medically known as urticaria) are red, itchy, raised areas of skin that appear in varying shapes and sizes. Many cases of hives are "idiopathic," meaning no cause is known. Others may be triggered by viral infections or medications.
In such cases, taking antihistaminics like Benadryl and application of calamine lotion is helpful. If the symptoms are severe then you may need topical steroids for which you have to consult a doctor.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. Treatment can be started only when the diagnosis is confirmed. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.