Pigmentation spots are caused by melanin, which is produced when skin is exposed to the sun. Normally, melanin is synthesised by melanocytes, which help to spread melanin all over the body to ensure an even tan. If this process is interrupted, melanin automatically stays in the most sensitive areas of the body, or areas that are often uncovered. This is why the face and the hands are the first victims of pigmentation spots.
Usually, pigmentation spots are seen in people over 40, as after 30 years your melanocytes decrease by 10-20% each decade. Some people who are genetically pre-disposed to these ‘sun-spots’ get them younger than 40. Antibiotics, psychotropic drugs and the contraceptive pill can also cause these spots, as can pregnancy. But the main cause is UVB and UVA – pigmentation spots usually come from years of sun exposure.