Ear fistula

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Classification according to ICD-10
H61.8 Other specified diseases of the external ear
- ear fistula
ICD-10 online (WHO version 2019)

The ear fistula , also known as the preauricular sinus , belongs, like the ear cyst and the ear appendage ("surplus auricle"), to the excess malformations that arise during embryonic development from germs spreading at the border between the first and second gill arch .

The disease, which occurs frequently in families, is rarely associated with a middle ear malformation and / or inner ear hearing loss, such as the extremely rare Fourman-Fourman syndrome .

Ear fistula at the attachment of the upper auricle

Classification

  • Type I ear fistulas contain skin epithelium, usually end blindly and can be viewed as a “double ear canal”.
  • Type II ear fistulas contain not only skin epithelium but also mesenchymal tissue such as ear cartilage.

root cause

Ear fistulas are caused by a malformation during embryonic development that occurs either spontaneously or as an autosomal dominant inheritance . More than 50% are one-sided, which is usually a spontaneous occurrence. In the case of bilateral occurrence, the inherited variant is more likely to be present, which is autosomal dominant with reduced expression (around 85%). According to today's view, the origin is an imperfect fusion of the six auricular cusps, three of which are located on the first and second gill arch . Chinese researchers have linked the genetic variant with the 8q11.1 – q13.3 gene locus. In the case of one-sided occurrence, the right ear is said to be affected more often, women more often than men. The incidence is given as 0.1% - 0.9% (for the USA); in Africa there are said to be incidences of 4% to 10%. Ear fistulas are sometimes associated with kidney abnormalities. In rare cases, they can be associated with Branchio-oto-renal syndrome and a number of other syndromes.

therapy

An ear fistula should be surgically removed if it leads to chronic inflammation or troublesome secretion around the auricle. In the case of children, one can certainly wait until they reach adulthood. Some fistulas open in front of the ear, mostly at the top of the auricle, others behind the ear. In preparation for the operation, they are often stained with dyes such as methylene blue . Type II ear fistulas can have a complicated course directly related to the parotid gland and facial nerve , making surgery difficult and demanding. It is important to completely remove the fistula or cyst during the procedure, otherwise it can recur .

Individual evidence

  1. ↑ Naumann, Helms, Herberhold: Oto-Rhino-Laryngologie in Klinik and Praxis, Volume 1. Stuttgart 1994, p. 12 f.
  2. ↑ KV Kumar Chowdary, N. Sateesh Chandra, R. Karthik Madesh: Preauricular sinus: a novel approach. In: Indian journal of otolaryngology and head and neck surgery: official publication of the Association of Otolaryngologists of India. Volume 65, Number 3, July 2013, pp. 234-236, doi : 10.1007 / s12070-012-0520-y , PMID 24427573 , PMC 3696150 (free full text).
  3. ↑ F. Zou, Y. Peng, X. Wang, A. Sun, W. Liu, S. Bai, H. Zhu, B. Gao, G. Feng, L. He: A locus for congenital preauricular fistula maps to chromosome 8q11.1-q13.3. In: Journal of human genetics. Volume 48, Number 3, 2003, pp. 155-158, doi : 10.1007 / s100380300024 , PMID 12624728 .
  4. ↑ Preauricular Sinus Infection - Causes and Treatments. . 1992. Retrieved September 5, 2016.
  5. ^ AK Leung, WL Robson: Association of preauricular sinuses and renal anomalies. In: Urology. Volume 40, Number 3, September 1992, pp. 259-261, PMID 1523751 .