The aging process is often associated with untoward effects on the neckline, including accumulation of fat, redundancy of the skin, skin laxity, and ptosis of the underlying anatomical structures1. Recently, the number of patients with neck wrinkles has been increasing, and an increasing number of young patients are affected with this problem. This situation could be due to the tendency of many people to tilt their head downward when using a computer or a smartphone; it is possible that such posture could create wrinkles on the neck skin. In these patients, very prominent horizontal wrinkles can be seen on the neck without the accumulation of fat, ptosis, or decreased skin laxity. Reducing the depth of wrinkles by creating a more homogeneous skin tone with a smoother texture helps achieve a more youthful appearance1.

Radiofrequency (RF) is the most widely used technique in dermatology for nonablative skin rejuvenation through its thermal effects2. Recent reports have shown improvement of the neck skin through treatment with nonablative RF devices2,3,4. Here, we present two cases of prominent neck wrinkles in young adults treated by using an intradermal RF device.

RF produces an electrical current that generates thermal effects through the resistance of the dermal and subcutaneous tissues. These thermal effects stimulate initial collagen contraction and a wound-healing response, which induce the remodeling of dermal collagen and tighten the skin tissues5.

In our cases, we used a novel bipolar, needle-type RF device (INNOFill; Pacific Pharma, Seoul, Korea). The entire RF needle was insulated with a biocompatible parylene layer, leaving the distal 1 mm exposed to act as the electrode in the tissue. A separate needle designed to apply RF was inserted into the skin to stimulate initial collagen contraction and the wound-healing response. Unlike the use of other RF devices, insertion of an RF needle directly into the dermis layer produces a high concentration of energy transported through microheating without causing thermal damage to the microarea, creating a very intense reaction6. In case 2, we decided to perform peeling with 30% GA to create a more homogeneous skin tone and a smoother texture. GA is widely used as a superficial peeling agent owing to its exfoliative properties7. Exposure of the skin to GA leads to reduced corneocyte adhesion, correction of abnormal keratinization in the infundibulum, decreased keratinocyte plugging, and ultimately decreased follicular occlusion8. Although the exact mechanism of action is unknown, it has been demonstrated that α-hydroxy acids improve fine wrinkles, melisma, hyperpigmentation disorder, acne, and rosacea by thinning the stratum corneum, promoting epidermolysis, dispersing basal layer melanin, and increasing collagen synthesis within the dermis9. Because of the efficacy of chemical peels, we considered that nonablative RF treatment combined with chemical peeling might have the synergistic effects of reducing wrinkles, creating a homogeneous skin tone, and achieving a smooth skin texture. Furthermore, insertion of a needle-type RF has the advantage of not aggravating the skin surface that is already irritated because of the chemical peeling.

Based on the clinical responses observed in the present cases, we propose that intradermal RF may be an effective modality for the treatment of neck wrinkles. However, further studies are needed to confirm the safety and efficacy of this treatment.