Nevus depigmentosus, or nevus achromicus, is a skin problem wherein specific areas of the skin appear to be hypopigmented or depigmented. The lesions of this skin disorder appear as light colored or white spots that are not elevated, are inborn or congenital, and are nonprogressive or do not spread or resolve with age. Unlike vitiligo, which is a multifactorial disease with destruction of epidermal melanocytes, and albinism, which results from disorders of melanocyte development or differentiation, nevus depigmentosus involves the decreased production of melanin by melanocytes. It may also be mistaken for a similar-looking skin disorder called nevus anemicus, but it does not redden after the application of friction, unlike nevus anemicus. Nevus depigmentosus cannot be treated, but can be hidden through the appropriate use of cosmetics.
The white or hypopigmented lesions do not increase in size, although an enlargement may be noted, but is often proportional to a child’s growth. They are usually limited to the trunk and the upper arms and legs. The pattern of distribution may appear as leaflike, linear, or segmented. Approximately 19% of people have these lesions at birth.
There is no pattern of inheritance in nevus depigmentosus, so it is not known whether this skin disorder is a dominant or recessive trait. Most newborns with nevus depigmentosus do not have any manifestations until they become infants or toddlers. The main pathology of nevus depigmentosus is a decreased production of melanin, thus localized albinism is not a proper description because albinism involves problems with the development or differentiation of melanocytes, or the melanin-producing cells responsible for human pigmentation.
To diagnose nevus depigmentosus, dermatologists use several criteria such as the presence of hypopigmented or white lesions from birth or early in life, lack of changes in distribution throughout life, lack of sensory disturbance in the affected area, and lack of hyperpigmentation surrounding the affected area. Associated symptoms are very rare, although some patients have shown symptoms such as seizures, mental retardation, sensitive skin, and yellow hair. Patients have reduced melanin and are more prone to sunburn, so it is best for them to always use sunscreen or sunblock products on affected areas. Probably the best way to deal with nevus depigmentosus lesions, particularly among self-conscious individuals, is to use cosmetics to cover affected areas. Excision or removal of the lesion using lasers may be performed only if a small area of the skin is involved, while another treatment option, called melanocyte-keratinocyte transplantation (MKTP), has limited success.