Collagen, used in wound repair, tends to overgrow in this area, sometimes producing a lump many times larger than that of the original scar. They can also range in color from pink to red. 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. If a keloid appears when someone is still growing, the keloid can continue to grow as well. Location
Keloids can develop in any place where skin trauma has occurred. They can be the result of pimples, insect bites, scratching, burns, or other skin injury. Keloid scars can develop after surgery. They are more common in some sites, such as the central chest (from a sternotomy), the back and shoulders (usually resulting from acne), and the ear lobes (from ear piercings). They can also occur on body piercings.The most common spots are earlobes, arms, pelvic region, and over the collar bone. Cause
Most skin injury types can contribute to scarring. This includes burns, acne scars, chickenpox scars, ear piercing, scratches, surgical incisions, and vaccination sites. According to the (US) National Center for Biotechnology Information, keloid scarring is common in young people between the ages of 10 and 20.
Drug induced pigmentation may take on many different appearances, one of the most common being a change in the color, or pigmentation, of the skin. Presentation
Cause
Drug-induced pigmentation of the skin may occur as a consequence of drug administration, and the mechanism may be postinflammatory hyperpigmentation in some cases, but frequently is related to actual deposition of the offending drug in the skin. : 125–6 The incidence of this change varies, and depends on the type of medication involved. Some of the most common drugs involved are NSAIDs, antimalarials, psychotropic drugs, Amiodarone, cytotoxic drugs, tetracyclines, and heavy metals such as silver and gold (which must be ingested, not just worn). Pathophysiology
There are 4 possible mechanisms to how this change may occur:
Accumulation of melanin, the skin pigment
Accumulation of drug or one of its products under any layer of the skin (usually the dermis or epidermis)
Accumulation of iron throughout the dermis from drug-induced post-inflammatory changes
The synthesis of special pigments, under direct influence of the drug

See also
Skin lesion

References


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