What causes Hyperpigmentation?

Hyperpigmentation can be caused by:

  • Sun damage,
  • Inflammation
  • Skin injuries e.g. infection, cuts, or due to Acne vulgaris
  • Laser damage
  • Post Inflammatory Hyperpigmentation (PIH) (These are dark and discolored spots that appear on the skin following infection.)
  • Hormones & contraceptives
  • Pregnancy

Diseases:

  • Addison’s disease
  • Cushing’s disease
  • Acanthasis nigricans
  • Melasma
  • Linea nigra
  • Smokers melanosis
  • Celiac disease
  • Tinea
  • Haemochromatosis
  • Mercury poisoning
  • Nelson’s syndrome

Asian, Mediterranean, or African skin tones are also more prone to hyperpigmentation, especially if they have excess sun exposure.

Dark patches are produced, as UV light stimulates the melanocytes to produce more Melanin (dark pigment, which gives colour to the skin, eyes & hair)

Excessive melanin production is dependent on two factors:

1) The size of the melanocytes (melanin producing cells)
In dark-skinned people, this cell is large and responds quickly to stimulation.

2) The stimulation of the Melanocytes.
UV light from the sun, heat & even indoor lighting can stimulate excessive melanin.

Some common names are given to typical dark marks e.g. Melasma or Chloasma (pregnancy), freckles etc., but these are not helpful in the treatment and only confuse people.

These are terms of dermatology used by experts to communicate or describe the dark mark but have no bearing on managing them.