Calluses on the side of the toes may be caused by callus, corns, plantar warts and other factors. 1. callus, corns: long time standing and walking, wearing shoes are not suitable, may make the toes by excessive friction, will make the toes on the side of the horny layer thickening, usually no other clinical symptoms. 2. metatarsal warts: usually caused by human papilloma virus infection, invasion of the toe area, it will make the callus-like plaque on the side of the toe, there may be oppressive pain, scraping will also cause bleeding. Calluses on the side of the toes, and there are other abnormal manifestations, it is recommended to consult a doctor for examination and treatment, to avoid causing other complications.