also described a pair of twins who developed keloids at the same time after vaccination. Case series have reported clinically severe forms of keloids in individuals with a positive family history and black African ethnic origin. Pathology
Histologically, keloids are fibrotic tumors characterized by a collection of atypical fibroblasts with excessive deposition of extracellular matrix components, especially collagen, fibronectin, elastin, and proteoglycans. Generally, they contain relatively acellular centers and thick, abundant collagen bundles that form nodules in the deep dermal portion of the lesion. Keloids present a therapeutic challenge that must be addressed, as these lesions can cause significant pain, pruritus (itching), and physical disfigurement. They may not improve in appearance over time and can limit mobility if located over a joint.Keloids 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. The frequency of occurrence is 15 times higher in highly pigmented people. People of African descent have increased risk of keloid occurrences. Treatments
Prevention of keloid scars in patients with a known predisposition to them includes preventing unnecessary trauma or surgery (such as ear piercing and elective mole removal) whenever possible. Any skin problems in predisposed individuals (e.g., acne, infections) should be treated as early as possible to minimize areas of inflammation.
Studies have shown that those with darker complexions are at a higher risk of keloid scarring as a result of skin trauma. They occur in 15–20% of individuals with sub-Saharan African, Asian or Latino ancestry, significantly less in those of a Caucasian background. Although it was previously believed that people with albinism did not get keloids, a recent report described the incidence of keloids in Africans with albinism. Keloids tend to have a genetic component, which means one is more likely to have keloids if one or both of their parents has them. However, no single gene has yet been identified which is a causing factor in keloid scarring but several susceptibility loci have been discovered, most notably in Chromosome 15. Genetics
People who have ancestry from Sub-Saharan Africa, Asia, or Latin America are more likely to develop a keloid. Among ethnic Chinese in Asia, the keloid is the most common skin condition. In the United States, keloids are more common in African Americans and Hispanic Americans than European Americans. Those who have a family history of keloids are also susceptible since about 1/3 of people who get keloids have a first-degree blood relative (mother, father, sister, brother, or child) who also gets keloids. This family trait is most common in people of African and/or Asian descent. Development of keloids among twins also lends credibility to existence of a genetic susceptibility to develop keloids. Marneros et al. (1) reported four sets of identical twins with keloids; Ramakrishnan et al.