I'm sorry to hear about the itching and the spot on your foot. Itching accompanied by a red or black spot could be due to several causes such as an allergic reaction, insect bite, fungal infection, or even a minor skin injury.

Here are some general steps you can follow for relief:

• Keep the area clean and dry. Wash gently with mild soap and water.
• Avoid scratching to prevent further irritation or infection.
• Apply a cool compress to reduce itching and inflammation.
• Over-the-counter antihistamines like levocetirizine (an anti-allergic medication) may help reduce itching if it is allergy-related. However, these should be taken only after consulting a doctor.
• Avoid irritants such as harsh soaps, detergents, or tight footwear.

Since the spot is red or black and persistent, it is important to have it evaluated by a dermatologist (skin specialist). They can examine the lesion closely, possibly perform tests if needed, and provide a precise diagnosis and appropriate treatment.

If you notice worsening symptoms such as increased pain, swelling, spreading redness, discharge, or fever, seek medical attention promptly.

Please consult a dermatologist for a thorough evaluation and tailored treatment plan.To narrow down potential causes, we will need some more information.Please tell me your age and gender.