Epidemiological analysis of keloids in Hong Kong Chinese patients

Abstract

Keloid, a rare disease for humans, infests the skin around the initial wound and extends. Since 1700 BC when it was first described, many researches have been trying to explore a deeper understanding of this disease and the mission never stops, for its still unknown etiopathogenesis.

Electronic search, performed in PubMed, Embase and HKU Library, has identified 230 eligible studies reporting a total of 533 cases of keloid in literature. The analysis shows that the weighted mean of patients’ age is 36.19, between the range of 13 and 62. Most studies report a mean/median age of patients between the 18s and the 30s. The weighted proportion of male patients to female patients is 0.83, indicating that females are more likely to catch the disease. Two fifths (40%) of keloid are in craniofacial areas while 15% take place in thoracodorsal areas.

Furthermore, the reports prove that TNF-α, IF-β, IL-6, IL-18, CTGF and SCF contribute to the formation of keloid. The receptors and inhibitors of P13K, MAPK, Sp13, mTOR and c-KIT are therapeutic potentialities. Surgery is the most fundamental way to relieve the symptoms of this disease, but adjuvant irradiation therapy is considered a more effective approach, considering its high recurrence rate. Besides, injection, laser, occlusive dressing, compression therapy and cryotherapy are also viable options.

We conducted a research of keloid in Hong Kong, Chinese on infected people from the age 1 to 86. The research results reveal that the ratio of male patients to females ones is 1:1.96. Keloid is most likely to happen from age 20 to 39 and from 60 to 69 among males and 40 to 59 among females. The mean ± SD age is 42.17 ± 19.75 years in males and 41.02 ± 19.20 years in females (p=0.583 >0.005). Moreover, the mean is 41.5 in males and 42.0 in females (p = 0.548 >0.005). For males, keloid occurs mainly on the chest and limbs, while for females, it is usually on the chest and head, suggesting a statistically significant difference（x^2=22.282，P=0.004<0.05）. Additionally, there is a significant difference between male and female patients who have keloid on their limbs (T=2.178, P=0.033<0.05). The mean age of onset of males much older than females, which was 39.7 and 31.94, respectively. Surgery was the most common cause of keloid in Hong Kong, followed by skin injury, burn and inflammation. In terms of treatment, most patients choose injections, followed by sheet dressing, excisional surgery and cream therapy. Laser removal of keloid is the least favoured choice. As for the treatment period, most patients are treated more than a year.

In conclusion, these findings provide more information of keloid and hopefully will serve as an indicator of prognosis and diagnosis for Hong Kong patients in the future. More investigations and researches should be conducted to offer a more thorough and profound understanding of this disease.