Causes and risk factors
The exact cause of this condition is not known. It is considered to be caused due to certain genetic factors. Mutation of gene GNAQ or GNA11 have been responsible for this condition. Normally the epidermis consist of the melanocytes which secret melanin, however in this condition the melanocytes are seen in dermis.
Clinical presentation:
Appearance of irregular brownish or bluish grey discoloration patch is the characteristic feature seen. The discoloration often resembles as if the area is bruised or tanned. Mostly the discoloration is seen unilaterally. Usually the discoloration is restricted to shoulder and upper arm. In some cases, decreased sensitivity of the affected area is also seen.
Investigations:
Usually to diagnose these birthmarks, no investigations are required. Clinical examination is sufficient for this. Skin biopsy and histological examination can also be done; however, it is rarely advised.
Treatment:
There is no effective treatment yet available for this condition. However, various treatment ways can be adopted. Use of laser therapy or intense pulse light for destruction of the melanocytes can also be done.
