[Ingrown toenail: when and how to treat?].

With an estimated prevalence of 2.5-5% of the western population, ingrown toenails are one of the most common nail diseases that leads patients to general physicians as well as to dermatological or surgical clinics. The cause of the disease is multifactorial, including genetic predisposition with a too wide nail plate, but also incorrect cutting of the nail and wearing of too tight shoes. Penetration of the sharp, lateral edge of the nail plate into the tissue results in inflammatory irritation of the lateral nail wall. The extent of the inflammation does not necessarily correlate with subjective symptoms, so that patients may describe severe pain even with low levels of inflammation. The big toe is most frequently affected. Several treatment approaches are available. Podiatric treatment such as tamponades or sulci protectors can improve the symptoms in mild cases. Surgical treatment primarily involves chemical matrixectomy (e.g., using phenol) or mechanical resection of the lateral matrix horn. The use of traumatic surgical techniques such as the so-called "Emmert plasty" or wedge excisions is not recommended.