Topical Benzoic Acid + Salicylic Acid is generally well tolerated when used as directed. Undesirable effects are most likely to occur when the medicine is used in younger children, in patients with impaired liver or kidneys, on broken or inflamed skin, in high concentrations, over large skin areas, prolonged use, and/or presence of occlusion (i.e., application on skin folds, use of plastic bandages or dressings that prevent air from circulating to the area being treated).
The following undesirable effects have been observed after topical application: Benzoic acid: Irritation, itchy rash, allergic reactions, may lead to salicylate toxicity.
Salicylic acid: Local irritation, skin inflammation, signs of salicylate toxicity (eg, thirst, tinnitus or ringing in the ears, loss of hearing, headache, dizziness, vomiting, diarrhea, depression and disorientation).
Allergic reactions including itchy rash, anaphylaxis and erythema multiforme (skin reaction characterized by small, red elevations or blisters arranged around a common center).