Patients with small keloid scars were selected for treatment with extended injections of Depo-Provera injection where lesions were secondary to post-acne, post-trauma, post-burns, prophylactic injections, and post-insect bites.
The post-surgical keloids were all between 2.0cm x 2.0cm – 8.5cm x 6.5cm. The lesions were located on the upper arm and anterior chest, of which recurred after surgical excision, and were treated with topical medication, freezing and other methods without significant improvement. The number of treatments was determined by the size of the lesion and the duration of the disease. The number of treatments depends on the size of the lesion and the duration of onset. Generally, 3–4 consecutive treatments are given for <3cm in diameter, and 6--8 consecutive treatments are given for >3cm. The scope of drug injection includes the epidermis and dermis within the keloid and 0.5cm outside the keloid. The efficacy criteria were as follows: cured: the lesions were completely flattened and softened, not higher than the plane; effective: more than 70% of the lesions were flattened and softened; improved: more than 30% of the lesions were flattened and softened; ineffective: no significant change in the lesions or <30% flattening and softening. Results: 9 out of 15 keloid scars were cured in 3 times, mostly keloid scars <3cm in diameter; 5 out of 7 times, with a cure rate of 93.3%. 1 case was effective, with a significant rate of 6.7%. Keloid scars are formed by excessive proliferation of collagen fibers and dermal fibers after dermal tissue injury. . Studies have shown that the proliferative activity of skin fibroblasts around the keloid is not similar to the central part of the keloid and is intermediate between the edge of the keloid and the normal skin. The presence of fibroblasts with abnormal biological activity in the 0.5 cm of skin surrounding the keloid may be one of the reasons for the infiltrative growth of the keloid and its susceptibility to recurrence after treatment. Different parts of the keloid show different growth characteristics, the closer the peripheral part the more active the fibroblasts proliferate and the lower the apoptosis rate. In addition to the original treatment area, the treatment area was extended to 0.5 cm beyond the keloid with good results. Depo-Provera is a steroid hormone that induces apoptosis of different fibroblasts cultured in vitro, and is currently the most effective drug for the treatment of hyperplastic keloids and keloid scars. Topical application reduces capillary wall permeability and edema formation, has antagonistic effects on hormones and prostaglandins, causes epidermal and dermal atrophy, and has a better effect on keloid scars. In addition, local injection of Depo-Provera can inhibit precollagen gene expression by suppressing PDEF gene transcription, inhibit type I and III collagen synthesis in in vivo scar fibroblasts, cause increased expression of C2mgc and p53 genes in scar tissue, and thus induce apoptosis in in vivo scar. The patients all achieved ideal treatment results, the keloid not only flattened but also did not expand to the surrounding area, and there were no complications such as skin breakdown and depression in the surrounding injection area. This method is effective in the treatment of keloid scars without significant complications, and is worth promoting. In conclusion, in order to obtain definite efficacy and to avoid complications to the maximum extent possible, it is necessary to pay attention to the fact that the injection should be made in the dermis, within a range of about 0.5 cm, not under the skin, and the total injection volume should not exceed 5 mL.