https://en.wikipedia.org/wiki/Microneedles

Although microneedling follows a general set of operational principles, the strategies before and after treatment vary significantly depending on different skin concerns and indications. From acne scars to melasma, from hair loss to stretch marks, each condition requires a customized approach. Understanding these differences helps both patients and practitioners make more informed decisions.

Acne Scars: Pursuing Depth and Intensity

Acne scars are typically depressed and located in the dermis. Before treatment, patients must first control active acne to avoid needling inflamed papules. During treatment, needle length is usually set between 1.5 and 2.0 millimeters, requiring strong penetration to release scar adhesions and stimulate collagen remodeling. Post-treatment, bleeding and crusting are noticeable, with a recovery period of approximately 5 to 7 days. Postoperative care emphasizes infection prevention and sun protection, as scarred areas are more prone to pigmentation. Typically, 4 to 6 sessions are required, spaced 4 weeks apart, with peak results achieved 3 to 6 months after the final treatment.

Melasma: Pursuing Gentleness and Suppression

The causes of melasma are complex, involving multiple factors such as estrogen, sun exposure, and inflammation. Before treatment, thyroid disorders and medication-induced triggers must be ruled out, and strict sun protection should be maintained for at least two weeks. During treatment, needle length should not exceed 0.5 millimeters to avoid overstimulating melanocytes and causing post-treatment hyperpigmentation. Topical agents such as tranexamic acid, glutathione, and vitamin C are commonly used for skin brightening. Post-treatment skin reactions are generally mild, but sun protection remains critical-sunscreen must be applied even indoors near windows. Treatment intervals can be shortened to every three weeks, with a typical course consisting of three to five sessions. It is especially important to note that if patients develop post-inflammatory pigmentation after treatment, management becomes significantly more difficult; therefore, "conservative" treatment is the primary principle.

Hair Loss: Pursuing Activation and Continuity

The goal of hair loss treatment is to awaken dormant hair follicles. Prior to treatment, a dermoscope should be used to confirm whether the follicles are closed; if they are completely closed, microneedling will be ineffective. During treatment, needle length typically ranges from 0.5 to 1.0 millimeters, stimulating blood supply around the follicles and activating stem cells. Post-treatment care is relatively simple-avoid washing your hair for 24 hours after the session. Consistency is key: hair loss treatment requires weekly sessions for at least 12 consecutive weeks to achieve noticeable results. Combining the therapy with minoxidil or PRP can enhance effectiveness. Hair density and diameter in the same area should be photographed before and after each treatment to objectively assess progress.

Stretch Marks: Focusing on Repair and Elasticity

Stretch marks result fundamentally from the rupture of collagen and elastic fibers in the dermis. Before treatment, it's essential to assess the color of the marks-red marks (early stage) respond better than white marks (chronic). During treatment, needle depth should range from 1.5 to 2.5 millimeters, combined with the delivery of growth factors or PRP. After treatment, purpuric bruising may appear and typically resolves within about a week. Usually, 5 to 8 sessions are required, spaced six weeks apart. Due to high skin tension in the abdominal area, strenuous exercise and stretching movements should be avoided post-treatment. The main outcomes include reduced mark width, lighter coloration, and improved skin firmness.

In short, microneedling has no "one-size-fits-all" approach. From diagnosis and classification before treatment to parameter adjustments during the procedure and post-treatment care plans, every step must follow the principle of "tailoring treatment to the condition." Only through precise matching can this powerful tool achieve its maximum effectiveness.