Phacomatoses are a rare group of diseases that affect the nervous system and manifest with skin lesions. They are inherited diseases, so their basis is genetic, and they are associated with numerous multiorgan tumours, hence the importance of knowledge of phacomatoses in the diagnostic process. The skin changes that occur in the course of these diseases are very characteristic and allow the course of the disease to be defined, which is of key importance for the therapeutic process.
Medicine is guided by the principle that the skin is a reflection of our organism and, as a result, many diseases "reflect" on our skin - including diseases that affect the nervous system. The skin changes that can then be observed are of great diagnostic importance and can tell a lot about the course of the disease. However, differential diagnosis is very important and can be a considerable challenge for the physician, mainly due to the many forms of skin lesions, hence the interdisciplinary approach is well established in the diagnostic process .
Phacomatoses are skin diseases characterised by specific skin lesions and bony proliferations that are dysplastic in nature or in the form of benign tumours with a neural location, and are included in the group of genodermatoses. The hallmark of these conditions is a defect in the genes responsible for coding for the mTOR signalling pathway protein, which is responsible for the stimulation, growth and polyfunction of cells in response to signals such as growth factors and nutrients .
Phakomatoses (phakoma - lesion, patch) are otherwise known as neurocutaneous diseases, and the literature also contains a term such as neurodermatoses. Genetics underlies this group of pathological disorders - they are characterised by the occurrence of numerous organ neoplasms, without omitting the endocrine glands. For this reason, it is very important for the doctor to be familiar with this group of disorders, the most common of which are von Recklinghausen's disease (neurofibromatosis), tuberous sclerosis (Bourneville-Pringle syndrome), von Hippel-Lindau syndrome, and Klippel-Trénaunay-Weber syndrome .
Phacomatoses are conditions whose genetic basis is usually monogenic. Mutations in the genes are responsible for alterations that disrupt the embryonic cotyledons and tissue primordia at a very early stage in a person's life - in the third or fourth week of foetal life. This results in dysplastic changes in organs of ectodermal origin, which include the skin, CNS and peripheral nervous system. Here we find the answer to why phacomatoses are referred to in the specialist literature as neuromusculoskeletal disorders (the lesions that appear in the course of the disease are present in both the nervous system and the skin) .