Swelling and pain in the big toe is usually due to a secondary bacterial infection caused by cracking of the keratinized layer of skin on the toe, or other causes. The infecting bacterium is usually Staphylococcus aureus, which causes an abscess between the toes or a furuncle infection. Early clinical manifestations are localized redness, swelling, heat and pain, usually requiring prompt treatment with oral or even intravenous antibiotics, antibiotic treatment first choice of penicillin or a generation of cephalosporin antibiotics. If it develops further, it may form an abscess between the toes, or purulent toenail, which may not heal, or may even lead to onychomycosis and require nail extraction. If a purulent toe infection develops, it usually requires prompt incision and drainage of the pus, as well as oral antibiotics or even intravenous antibiotics.