Skin pigmentation disorders 

Skin pigmentation disorders are caused when there is an excessive or reduced production of melanin. It results in the skin appearing blotchy or discolored, darker or lighter.  This pigment is responsible for the color of the skin, eye and hair and is also responsible for forming a barrier against the ultraviolet radiation. 

Skin pigmentation disorders results in the skin appearing blotchy or discolored, darker or lighter.  Pigmentation problems are universal; some, like age spots, are quite common while others, such as albinism (caused by recessive genes), are very rare. 

Hypopigmentation is caused when the body fails to produce adequate melanin. The classical examples are the two conditions, albinism and vitiligo. 

• Albinism is a genetic condition that results in the complete absence of pigment. Hence an Albino typically has a pale skin, white, yellow or pale hair, and light eyes. Visual impairment and skin cancer are common among people with albinism. 
  
• Vitilgo is a condition characterized by smooth, depigmented white spots on the skin. It affects almost 2% of the population and is more evident in people with dark coloured skin. Some researches believe it to be an autoimmune disorder. Others associate it with Addison’s disease and hyperthyroidism 
  

• Lamellar ichthyosis  (‘fish scale’ disease) an inherited disease characterized  by dark, dry and scaly  patches of skin.
• Lichen simplex chronicus  is a skin disorder in which dark  patches develop. It  is often accompanied by severe itching. 
• Melasma, is another case of hyperpigmentation of the skin, that commonly occurs during pregnancy due to hormones. It can also occur in women on hormone replacement. Here,  a discoloration develops over the bridge  of the nose and cheeks. This often disappears after childbirth. 
  
• People with systemic lupus, an autoimmune disease, may develop  a butterfly-shaped, dark- colored mask on their faces. 
• Moles, age spots, freckles  and birthmarks, are other examples of hyperpigmentation. They are all usually harmless.