Abstract
The term phacomatosis is used to indicate two or more different types of genetically determined cutaneous lesions are contemporarily present, such as phacomatosis pigmentovascularis or phacomatosis pigmentokeratotica. The first observation of a newborn presenting with segmental café au lait macules combined with an aberrant Mongolian spot, led some authors to hypothesize that this singular association was not a coincidence, but the result of twin-spotting phenomenon. In the analogy to other similarly named entities, they coined the term ‘phacomatosis pigmento-pigmentalis’.
Financial & competing interests disclosure
The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
No writing assistance was utilized in the production of this manuscript.
Key issues
• The term ‘phacomatosis’ derives from the Greek word ζακóς, and it is used to identify genetic diseases in which two or more different types of nevi are contemporarily present, such as phacomatosis pigmentovascularis or phacomatosis pigmentokeratotica.
• Phacomatosis pigmento-pigmentaria is an association of two pigmented nevi or pigmented anomalies of nevoid character.
• The necessity of adding a new phacomatosis in the group comes from the observation of large variegate group of different associations of nevoid pigmentary disorders in the same subject, which did not fulfill the criteria for other phacomatoses.
• It probably results from a twin-spotting phenomenon.
• Different associations of pigmentary disorders have been described under the same name of phacomatosis pigmento-pigmentaria.
• So far, no criteria exist to make diagnosis of phacomatosis pigmento-pigmentaria.
• Literature contains a large group of cutaneous disorders characterized by the apparently causal association of two different pigmentary disorders.
• The description of this group of diseases with the specific denomination of ‘phacomatosis pigmento-pigmentaria’ permits to unify under a common shared genetic and developmental mechanism clinically different pigmentary disorders.