Indications
Benzoic acid is used on the skin to treat fungal infections such as:
- Ringworm of the body (tinea corporis).
- Athlete’s foot (tinea pedis).
- Fungal infection of the groin (jock itch).
- Fungal infection of the hands and thick, scaly fungal patches.
It is almost always combined with Salicylic Acid in an ointment (commonly known as Whitfield’s ointment).
How It Works
Benzoic acid stops fungi from growing. Salicylic Acid softens and loosens the thick, scaly top layer of skin (a keratolytic effect), so the infected skin peels away and the antifungal can reach the fungus.
Dosage and Administration
Wash and dry the affected skin, then apply a thin layer to the patch and a little of the skin around it, usually twice a day. Continue for 1 to 2 weeks after the skin looks clear to stop the infection coming back; most infections need 2 to 4 weeks, and the feet may need longer. Wash your hands after applying, unless the hands are being treated. For use on the skin only.
Interactions
Avoid using other skin products on the same area, especially other peeling products such as Benzoyl Peroxide or Tretinoin, as this can increase irritation. No important interactions with medicines taken by mouth are expected when used on small areas.
Contraindications
- Allergy to benzoic acid, salicylic acid or any ingredient of the product.
- Broken, raw or weeping skin.
- Use in or near the eyes, mouth or other moist linings of the body.
Side Effects
Common: stinging, burning, redness, dryness and peeling where it is applied.
Stop using it and get urgent medical help for swelling of the face or lips, difficulty breathing, severe blistering or spreading painful redness, or signs of salicylate poisoning after use on large areas (ringing in the ears, fast breathing, nausea, dizziness).
Pregnancy and Lactation
Use on small areas for a short time is generally considered acceptable; avoid large areas and long-term use, and ask your doctor first. When breastfeeding, do not apply it to the breast or nipple.
Precautions and Warnings
For external use only; keep away from the eyes. Do not use on children under 2 years unless a doctor advises it, and avoid large areas in children. People with diabetes or poor circulation should ask a doctor before treating the feet. Keep the area clean and dry and do not cover it with tight dressings. Infections of the scalp or nails usually need tablets; see a doctor if there is no improvement after 2 to 4 weeks.
Overdose
Using too much on the skin mainly causes irritation; wash off the excess. If it is swallowed, it may cause nausea, vomiting and stomach pain, and the Salicylic Acid can be harmful, especially to children; seek medical help straight away.
Therapeutic Class
Topical antifungal with keratolytic (skin-softening) action.
Storage
Store below 30°C in a dry place, away from light and out of the reach of children. Keep the container tightly closed.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.