I'm sorry to hear that you're experiencing a painful skin issue on your left leg that is affecting your ability to walk and run. This sounds quite uncomfortable and could be due to an infection or inflammation of the skin.

There is a topical medication called Fucidin H Cream, which contains fusidic acid (an antibiotic) and hydrocortisone acetate (a corticosteroid). This cream is used to treat bacterial skin infections and inflammatory skin conditions like atopic dermatitis. It works by reducing bacteria and calming inflammation, redness, and itching.

However, it is important to have a proper evaluation by a dermatologist or a doctor who can examine the affected area, confirm the diagnosis, and prescribe the appropriate treatment. Avoid self-medicating without professional advice, especially since some skin conditions require specific care.

If the pain worsens, the skin shows signs of spreading infection (such as increased redness, swelling, warmth, or pus), or if you develop fever, please seek urgent medical attention.

Recommendations:

• Consult a dermatologist promptly for an accurate diagnosis and treatment plan.
• Avoid scratching or irritating the affected skin.
• Keep the area clean and dry.
• Follow the doctor's instructions carefully if prescribed any topical or oral medications.

If you experience severe pain, difficulty walking, or signs of systemic infection, consider visiting an emergency department immediately.To narrow down potential causes, we will need some more information.Please tell me your age and gender. I understand you have a painful skin issue on your left leg that affects your ability to walk and run.