What are the causes of getting keloids, particularly small sized keloids? Can it be stress induced?

Keloids expand in claw like growths over normal skin. They have the capability to hurt with a needle-like pain or to itch without warning, although the degree of sensation varies from patient to patient.

If the keloid becomes infected, it may ulcerate. The only treatment is to remove the scar completely. However, the probability that the resulting surgery scar will also become a keloid is high, usually greater than 50%.

Keloids form within scar tissue. Collagen, used in wound repair, tends to overgrow in this area, sometimes producing a lump many times larger than that of the original scar. Although they usually occur at the site of an injury, keloids can also arise spontaneously. They can occur at the site of a piercing and even from something as simple as a pimple or scratch. They can occur as a result of severe acne or chickenpox scarring, infection at a wound site, repeated trauma to an area, excessive skin tension during wound closure or a foreign body in a wound. Keloids can sometimes be sensitive to chlorine (consult your dermatologist if faced with this problem).

They affect both sexes equally although the incidence in young female patients has been reported to be higher than in young males, probably reflecting the greater frequency of earlobe piercing among women. There is a fifteen times higher frequency of occurrence in highly pigmented people. It is speculated that people who possess any degree of African descent, regardless of skin color, may be especially susceptible to keloid occurrences.

Keloid is the tissue that scars are made of.

Keliods are overgrowth of scar tissue. This is more common in the African and African-American communities. What would ordinarily be a simple scar the the average person will develop into a large growth for the affected individual. I do not believe that there is an environmental cause, I think that it is more genetic predisposition.

No- It is totally genetic and you cannot do anything except take systemic steroidal medications to stop it occurring (and this meds are not available to stop scarring).
It is more common in people with darker skin.

there are some treatments for them once theuy have occurred and while you are healing.

the most effective and well researched is wearing a piece of silicone sheet over the area for approx 6 months which reduces the lumpiness and red/angriness of the scar.
this is called cica care and it made by smith and nephew

other treatments which you will see advertised such as bio oil and vit E have little efficiency.