Pincer Nail Deformity in an African American Patient Corrected by Fractionated Carbon Dioxide Laser

Pincer nail deformity is a painful nail condition characterized by excessive transverse curvature of the nail plate that pinches the surrounding tissue.¹ This condition primarily involves the toenail of the hallux and is more frequently observed in older individuals.¹ Management of a pincer nail typically involves nail braces or surgical removal.¹ These managements usually fall short of providing long-term relief and satisfaction cosmetically.¹ Fractionated Carbon Dioxide (fCO₂) laser therapy offers an advanced option in treating severe cases. fCO₂ laser can precisely target the nail matrix without causing extensive damage to surrounding tissues.² However, laser treatment for skin of color patients presents with more complexity, including higher risks of post-inflammatory hyperpigmentation (PIH) and scarring.³ These complications are more common in individuals with darker skin tones. Risk of hyperpigmentation, particularly in skin of color patients, deters many clinicians and patients from utilizing fCO₂.⁴ Research indicates that up to 16% of individuals with skin of color may develop hyperpigmentation after laser procedures.⁴ In addition to other potential complications, such as scarring.4 Advances in laser technology have made it possible to minimize these risks if appropriate settings are used.⁵ Customized treatment protocols and proper post-treatment care have been shown to reduce the risks of adverse outcomes, highlighting the need to address specific concerns, especially in patients with skin of color, and empower them with confidence in their treatment options.⁵ Case Description A 78-year-old African American female (Fitzpatrick type V) presented with a painful right thumbnail deformity that had been present since September 2021. She reported significant pain that impaired her ability to perform daily activities. Prior treatments, including an incision and drainage (I&D) with matricectomy, and later trimming of the distal nail with application of a nail brace failed to provide relief. The patient’s medical history included diabetes mellitus (DM), hypertension (HTN), and a history of tobacco use, contributing to the complexity of her case. Physical examination revealed a tender pincer nail deformity characterized by inward-curving lateral edges. Prior to the procedure, an eutectic mixture of local anesthetics (EMLA) was applied under occlusion for 60 minutes from the distal interphalangeal (DIP) joint to the fingertip. The patient was treated with a fCO₂ laser (DEKA SmartXide DOT, Florence, Italy) in DOT mode. The laser settings included: a rectangular shape with a 60% size, a 4/10 ratio, and a power of 15 W. Spacing was set to 650 microns, with a dwell time of 500 microseconds and a stack of 1. The treatment area focused on the radial side of the lateral right thumb nail, including 1 to 2 mm of the lateral nail fold and 2 mm of the proximal nail fold, specifically targeting the nail matrix. The fCO₂ laser was pulsed 4 times on the lateral endpoint to ensure adequate coverage. Post-treatment care consisted of applying triamcinolone 0.1% ointment to the treated finger to reduce inflammation, followed by covering the area with Telfa dressing, gauze, and a coband