There are two main types of pigmentation inconsistencies; hyperpigmentation and hypopigmentation.
What is hyperpigmentation and what causes it?
Hyperpigmentation is where patches of the skin appear darker than the skin’s normal colour.
Hyper-pigmentation is caused by an increase in melanin, the substance in the body that is responsible for colour. Certain conditions such as pregnancy may cause a greater production of melanin. Exposure to sunlight is also a major cause of hyperpigmentation, and will darken already pigmented areas.
An example of hyper-pigmentation is melanoma; this condition is characterised by tan or brown patches typically on the face. It can also appear during pregnancy, and often disappears after.
What is hypopigmentation?
Hypopigmentation is where patches of the skin appear lighter than the skin’s normal colour.
Hypopigmentation is characterised in three groups:
Vitiligo – small, smooth white patches on the skin.
Albinism – an inherited disorder where the enzyme producing melanin is not existent, causing a complete lack in skin pigmentation and hair.
Skin damage – infections, blisters, burns and other traumas to the skin can cause the pigment to take a long time to return to the skin.
What are lentigenes?
Lentigines are flat brown lesions which do not darken following sun exposure. They may be any size from 5-20mm and may be irregular in shape.