Special Population Alerts: Who Should Avoid Microneedling?

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

Although microneedling has a wide range of applications, it is not suitable for everyone. As the technique involves the active disruption of the skin barrier and the deep delivery of drugs or active ingredients, certain special populations face higher risks of side effects, potentially leading to the worsening of existing conditions. Identifying these contraindicated groups is a bottom line that responsible professionals must uphold.

Patients with active skin diseases are absolute contraindications. Performing microneedling on lesions of active eczema, psoriasis, flat warts, or herpes zoster may lead to the dissemination of viruses or bacteria, causing infection spread or the Koebner phenomenon (isomorphic response). The Koebner phenomenon refers to the appearance of similar skin lesions at sites of trauma outside the original affected area. In psoriasis patients, the incidence of this phenomenon ranges from 30% to 50%; an improper microneedling session could trigger a systemic flare-up. Therefore, any active skin disease must be treated to a stable phase before considering microneedling intervention.

Individuals prone to keloid scarring require extreme caution. The formation of keloids and hypertrophic scars is closely related to genetic predisposition. For these patients, even the micro-trauma caused by microneedling may trigger abnormal collagen deposition, resulting in raised scar tissue at the treatment site, which would be counterproductive. Clinically, a preliminary assessment can be made by asking about significant scarring following previous surgeries or injuries. For patients highly suspected of having a keloid tendency, it is advisable to perform a small-area test on the inner forearm and observe for 3 to 6 months before deciding on further treatment.

Pregnant and lactating women constitute a relative contraindication. While there is currently no direct evidence that microneedling harms the fetus, skin sensitivity increases during pregnancy, and microneedling may induce a more intense inflammatory response than usual. More importantly, certain ingredients often used in conjunction with microneedling-such as salicylic acid, retinoids, and hydroquinone-have been proven teratogenic or capable of secreting into breast milk. Therefore, unless treating pregnancy-specific conditions (like stretch marks), microneedling for cosmetic purposes is not recommended during this period.

Patients taking specific medications also need heightened vigilance. Anticoagulants such as aspirin, warfarin, and clopidogrel significantly increase the risk of bleeding and bruising. Retinoid medications like isotretinoin inhibit the normal differentiation of epithelial cells, delaying wound healing; treatment is generally advised only 6 months after discontinuation. Immunosuppressants such as corticosteroids and cyclosporine weaken the body's anti-infection capabilities, multiplying the risk of post-operative infection.

Furthermore, diabetic patients, those with coagulation disorders, and individuals with severe immunodeficiency should be considered cautious candidates. Diabetic patients' microcirculation impairment and delayed healing properties make them prone to secondary infections that are difficult to heal. Those with coagulation dysfunction may experience uncontrolled bleeding, while immunocompromised individuals lack the basic ability to fend off bacterial invasion.

The appeal of microneedling lies in its "minimally invasive" nature, but "minimally invasive" does not mean "risk-free." Screening indications for every patient is the ultimate respect for the technology.