Royal Free Hospital   London  nw3

A great variety of disorders can cause brown marks.
  
A consultation with a specialist will be necessary for a 
diagnosis and to discuss treatment options.

Depending on the diagnosis treatments include 
prescription creams, laser, IPL and excisional biopsy. 
Pigment disorders can be difficult to improve and 
no treatment may be possible. Occasionally serious 
diseases may be found.

There is further guidance in this advice sheet.