Connective tissue nevi are hamartomas in which one or several components of the dermis is altered. Lesions in which collagen predominates are called collagenomas; lesions in which elastin predominates are called elastomas. A nevus mucinosis is a lesion in which an alteration in the amount of dermal glycosaminoglycan is present. The name nevus mucinosis is also used for lesions in which an alteration in more than one dermal component is present.
Connective tissue nevi may be solitary or multiple, sporadic or inherited. They may occur as isolated skin lesions, or they may be associated with a number of syndromes. One report described a collagenoma that occurred on the bulbar conjunctiva. 
Zosteriform connective tissue nevus is considered to be a separate entity because of its distribution and histopathologic characteristics.
The cause of connective tissue nevi is unknown. However, note that osteopoikilosis with or without the skin manifestations of Buschke-Ollendorf syndrome and with or without melorheostosis can be caused by heterozygosity for loss-of-function mutations in LEMD3,  also called MAN1, which encodes an inner nuclear membrane protein.
The prevalence of connective tissue nevus is rare worldwide.
No racial predilection has been reported for connective tissue nevi.
No sexual predilection is described for connective tissue nevus.
The age of onset of a connective tissue nevus depends on the type of lesion. Collagenomas and elastomas generally present during the postpubertal period. In Buschke-Ollendorf syndrome, the skin changes may be delayed until adulthood. Nevus mucinosis may present at birth, during childhood, or in adolescence.