Cause and diagnosis of Alopecia Areata (AA)

Experts assume that AA is an immune system disorder. It is certain that the patches of hair loss are surrounded by inflamed cells secreting substances which hinder or inhibit hair growth.

In Bonn, human geneticists work on the decoding of the genetic basis of this disease, which has a certain hereditary component. In addition to the HLA type, several potentially involved genes have also been targeted, which also play a role in the development of other autoimmune diseases such as type 1 diabetes and rheumatism. In the meantime, several scientists have started collaborating internationally on this subject, since in-depth research is possible only with a very large DNA databank of the affected persons, in order to find a solution to the problem.

The recent GWAS (genome-wide association study) has come up with ground-breaking new findings on human genome localizations, where gene changes leading to the onset of Alopecia Areata can take place. Further analysis and detailed investigation of the GWAS results will be conducted in Bonn by an international group of scientists including geneticists in the near future. There are other scientific communities researching the possible triggering factors for Alopecia Areata. It is suspected that there are at least four or five factors that must be combined in order for the antibodies to form. To date, no breakthrough results have been published. The assumption is that the immune system must operate at full blast, so to say, to form these “false” antibodies.


This disease has already been described by Hippocrates. It was called ‘fox scabies’ or ‘fox disease’ at that time, because a fox’s coat usually has a patchy appearance. The disease is therefore not caused by environmental pollution. There are also no indications that hormonal disorders might be the triggering factors, since this disease affects people of different age and sex.

In children, Alopecia Areata occurs mainly between the ages of 3-12. However, before a specific treatment can be started, the Alopecia Areata must be confirmed. Other diseases such as Tinea Capitis, a fungus-induced infection of scalp skin, as well as cases of conscious or unconscious hair pulling (Trichotillomania) or hair cropping (Trichotomnomania) by patients themselves can be quite similar to spot baldness. In the latter case, the major cause is patient’s psychological tension, which can be detected in intensive discussions with children affected by this condition.