Micro-punch matrix drilling for a nasal hypertrophic scar: A case report

Abstract

BACKGROUND

Hypertrophic scars on the nose are common due to the high activity of sebaceous glands and significant skin tension in this area. Current standard treatments include laser therapy and intralesional drug (e.g., corticosteroid) injection; however, the results remain unsatisfactory for certain recalcitrant, focal, raised scars. Here, we describe a patient with a hypertrophic scar on the nose treated with micro-punch matrix drilling.

CASE SUMMARY

A 40-year-old female patient was admitted to our hospital with a one-year history of a nasal hypertrophic scar caused by self-squeezing and scratching following deep folliculitis. The patient had previously undergone carbon dioxide fractional laser therapy with unsatisfactory results. Following treatment with the 0.5 mm micro-punch matrix drilling technique, the wound healed well, the scar elevation was significantly flattened, and no adverse reactions (infection, recurrence, or pigment abnormalities) were observed.

CONCLUSION

The micro-punch technique is a minimally invasive and a potentially useful option in this patient with a focal hypertrophic scar. This suggests that it may serve as a promising alternative for selected hypertrophic scars that are unresponsive to conventional therapies, though further studies are required to confirm its broader applicability.

Key Words: Micro-punch; Matrix drilling; Hypertrophic scar; Nasal scar; Minimally-invasive therapy; Case report

Core Tip: The treatment of hypertrophic scars on the nose is challenging due to high skin tension and rich sebaceous glands in this area. Conventional laser or intralesional injections often yield unsatisfactory results for recalcitrant focal lesions. We report a case of nasal hypertrophic scar successfully flattened using a 0.5 mm micro‑punch matrix drilling technique, with no recurrence or adverse effects. The micro‑punch approach may serve as a simple, safe, and promising alternative for this patient and warrants further investigation in similar cases.

INTRODUCTION

Hypertrophic scar is a common outcome of excessive repair of dermal fibrous tissue following skin injury[1]. When occurring on the face, it severely affects aesthetics and the patient’s psychological well-being. The nasal skin is characterized by high tension and abundant sebaceous glands, making it prone to hypertrophic scarring and presents significant therapeutic challenges. While traditional methods such as lasers and intralesional injections have shown some efficacy, the results remain unsatisfactory for certain recalcitrant, focal, raised scars[2,3].

Micro-punch matrix drilling is a minimally invasive procedure for hypertrophic scars. It involves creating multiple punctate defects with a small-diameter punch to physically disrupt fibrotic tissue, rather than complete excision of the entire lesion or grafting of donor skin. Various punch-based techniques have been explored for the treatment of hypertrophic scars. Existing approaches can be broadly categorized into three types: Punch excision, which removes the entire lesion or its core with a punch biopsy tool; mini-punch combined with adjuvant therapies, where smaller punches are used as a debulking step before other treatments like photodynamic therapy or radiotherapy; and micro-punch grafting, which involves implanting donor skin or hair follicles into the punch sites to promote regeneration. The mini-punch technique, combined with photodynamic therapy, has been reported for mandibular keloids and hypertrophic scars, showing favorable outcomes with low recurrence rates[3]. These approaches share a common principle: Physically removing portions of fibrotic scar tissue to reduce volume and create fresh wound beds that promote physiological skin regeneration. The micro-punch matrix drilling technique we employed is conceptually aligned with the second category, focusing on physical debulking and micro-channel creation to facilitate healing, rather than complete excision or grafting. In contrast, ablative fractional laser relies on controlled thermal injury to form micro-thermal zones, remodelling pre-existing scar collagen rather than removing the bulk of fibrotic tissue[4]. The depth of laser penetration has been identified as a critical determinant of clinical response, with insufficient penetration limiting efficacy in dense, thick scars[5]. Such mechanistic differences may bring distinct clinical implications when managing thick nasal hypertrophic scars.

We describe a case of nasal hypertrophic scar which was significantly improved following micro-punch treatment, aiming to contribute to the growing body of evidence on the clinical application of this technique. To our knowledge, reports on the use of micro-punch matrix drilling as a sole therapy for a small, localized, and recalcitrant nasal hypertrophic scar are limited, and this case highlights the potential of this minimally invasive approach as a standalone procedure for a cosmetically sensitive area.

CASE PRESENTATION

Chief complaints

A 40-year-old female presented with a one-year history of a raised nasal scar.

History of present illness

The condition began with recurrent deep folliculitis on the nose approximately one year ago. She reported no pain, itching, or tenderness associated with the scar, but experienced considerable cosmetic distress due to its visibility on the nose. The patient frequently squeezed and scratched the affected areas, which subsequently led to a raised, firm scar on the nasal dorsum. The scar was stable without signs of active infection. She had undergone carbon dioxide fractional laser therapy twice at another institution (3-month intervals). According to the patient, the scar was temporarily flattened after each session but gradually relapsed to its original height within several weeks. The interval between her last laser session and the micro-punch procedure at our hospital was approximately 6 months. The specific treatment parameters were unavailable due to loss of external medical records and the patient’s inability to recall.

History of past illness

The patient’s past medical history was unremarkable except for a forehead scar excision (no keloid formation).

Personal and family history

The patient denied any history of smoking, regular medication, or known drug allergies. She also reported no family history of abnormal scarring or keloid formation elsewhere on the body.

Physical examination

A skin-colored, firm, raised hypertrophic scar measuring approximately 6 mm × 5 mm × 1.5 mm was observed above the left alar groove and adjacent to the nasal tip. The lesion had clear borders and a smooth surface, with no ulceration (Figure 1A). Preoperatively, the scar was assessed using the Vancouver Scar Scale (VSS), yielding a score of 5 (pigmentation: 1, vascularity: 1, pliability: 2, height: 1)[6].

Figure 1 Hypertrophic scar before and after treatment. A: A shiny, skin-colored, raised hypertrophic scar is visible on the nasal dorsum, just above the left alar groove and adjacent to the nasal tip, prior to treatment; B: Intraoperative view showing the immediate appearance after micro-punch matrix drilling; C: At 3 months postoperatively, the scar is flat and the color has largely returned to normal.

Laboratory examinations

No laboratory were performed. The diagnosis was made based on clinical presentation alone.

Imaging examinations

Routine preoperative blood tests, including complete blood count and infectious disease screening, were performed as per standard institutional protocol. No diagnostic laboratory or imaging examinations were required for establishing the diagnosis, which was made based on clinical presentation alone. Dermoscopy, biopsy, and microbiological cultures were not performed as the clinical features were characteristic and unequivocal for a post-inflammatory hypertrophic scar, and there were no signs of active infection or malignancy to warrant further testing. Diagnostic assessment: The diagnosis of hypertrophic scar was based on clinical findings: The lesion remained confined to the original injury site with no peripheral extension, and the patient had no personal or family history of keloid. Dermatofibroma and cutaneous neoplasms were excluded by the history of post-inflammatory scarring and the absence of atypical features. No further diagnostic testing was required, as the presentation was characteristic and there were no signs of active infection or malignancy.

FINAL DIAGNOSIS

Nasal hypertrophic scar (post-folliculitis).

TREATMENT

Informed consent was obtained. Before the procedure, the lesion and surrounding skin were carefully examined. No evidence of active folliculitis, such as erythema, pustules, tenderness, or warmth, was observed. The procedure was therefore performed electively. The patient’s face was cleansed, photographs were taken for records, using a standardized protocol with consistent distance, angle, and lighting conditions before the procedure (Figure 1A), immediately post-procedure (Figure 1B), and at the 3-month follow-up (Figure 1C). Preoperative blood tests (infectious disease screening and complete blood count) were performed.

Local infiltration anesthesia was administered to the lesion and surrounding area using 2% lidocaine with 0.1% epinephrine.

The surgical area was disinfected with iodophor three times and draped. A dense matrix drilling pattern was designed for the raised scar area and marked with gentian violet. A sterile 0.5 mm micro-punch (needle length: 4 mm) was used to drill to the mid-dermis, with uniform distribution and intervals of approximately 1-2 mm. A total of 11 punch sites were created, covering approximately 80% of the scar surface. The procedure lasted approximately 15 minutes, with minimal bleeding (approximately 0.5 mL) that was easily controlled by local compression. All punched fibrous tissue was completely removed. Small amounts of fibrous tissue were extracted by the punch, leaving a punctate microporous wound surface (Figure 1B). The area was irrigated with saline and compressed for hemostasis.

Chlortetracycline hydrochloride eye ointment (0.5%) was applied topically immediately after the procedure, and the area was covered with a sterile dressing for 24 hours. The patient was instructed to keep the wound clean and dry, perform daily wet compresses with sterile normal saline for 20 minutes, twice daily until healed, and avoid sun exposure and scratching. Considering the small wound size, no additional tension-reduction measures and oral antibiotics were applied.

OUTCOME AND FOLLOW-UP

Scabs were shed after one week, with good healing of the punctate wounds. At three months postoperatively, the raised scar was significantly flattened, the texture softened, and the color approximated the surrounding skin (Figure 1C). The VSS score decreased to 2 (pigmentation: 1, vascularity: 1, pliability: 0, height: 0). At the 6-month follow-up, the patient was evaluated in person. Physical examination confirmed that the scar remained flat and stable with no signs of recurrence, and the VSS score remained at 2. Standardized photographic documentation at 6 months was not available. The patient reported no pain, itching, or tenderness at the scar site, and expressed high satisfaction with the cosmetic outcome based on verbal feedback during the visit. No complications such as infection, bleeding, or dyspigmentation occurred. During the follow-up period, no additional scar-directed treatments, including silicone gel sheets, pressure therapy, corticosteroid injections, or laser therapy, were administered (Tables 1 and 2). The patient was advised to use broad-spectrum sunscreen (SPF 50+) on the treated area.

Table 1 Clinical timeline.

Time point	Event
1 year prior	Onset of recurrent deep folliculitis on the nose; hypertrophic scar developed after self-squeezing and scratching
9 months prior	First fractional CO2 laser session at an outside institution
6 months prior	Second fractional CO2 laser session at an outside institution (3 months after the first session); scar temporarily flattened after each session but relapsed within weeks
Day 0 (index procedure)	Micro-punch matrix drilling performed at our hospital (6 months after the last laser session)
1 week post-procedure	Scabs shed; punctate wounds healed well
3 months post-procedure	Scar significantly flattened (VSS: 5 → 2)
6 months post-procedure	Scar remained flat and stable (VSS: 2); no recurrence or adverse effects

VSS: Vancouver Scar Scale; CO₂: Carbon dioxide.

Table 2 Vancouver Scar Scale component scores and complications at each time point.

Time point	Pigmentation	Vascularity	Pliability	Height	Total VSS	Complications
Baseline (preoperative)	1	1	2	1	5	None
1 week post-procedure	-	-	-	-	-	None (wound healing well)
3 months post-procedure	1	1	0	0	2	None
6 months post-procedure	1	1	0	0	2	None (no recurrence)

VSS: Vancouver Scar Scale.

DISCUSSION

The core of hypertrophic scar treatment lies in inhibiting fibroblast hyperproliferation and promoting collagen remodeling[7]. The poor response to fractional laser in this case may be hypothesized to relate to the dense nature of the scar tissue, which could have limited adequate optical penetration and attenuated the thermal remodeling effect of the laser[5]. However, as the specific treatment parameters were unavailable, this interpretation remains speculative.

It is also important to acknowledge that factors other than the micro-punch procedure itself may have contributed to the observed improvement. The patient had ceased self-manipulation of the lesion before treatment, and the postoperative care protocol, including wound hygiene and sun protection, may have facilitated healing. Additionally, spontaneous scar maturation over time cannot be entirely excluded, although the scar had remained stable for approximately one year before the procedure, making spontaneous regression less likely.

As elaborated in the introduction, the micro-punch technique offers distinct physical advantages. In this specific patient, the 0.5 mm punches directly excised the core of the resistant fibrotic tissue, achieving immediate debulking. Meanwhile, the surrounding micro-channels provided a scaffold for rapid re-epithelialization from adjacent normal skin, avoiding the thermal damage and prolonged inflammation commonly associated with lasers. In this case, the micro-punch technique was associated with good wound healing and no reported complications. Unlike laser therapy, which relies on thermal injury, micro-punch physically removes fibrotic tissue. This mechanistic difference may offer practical advantages for small, localized scars, although direct comparative studies are lacking. In our case, the favorable outcome was also likely supported by the appropriate punch depth (mid-dermis) and density (1-2 mm intervals), which balanced effective scar disruption with rapid wound healing.

To our knowledge, reports on the use of micro-punch matrix drilling as a sole therapy for nasal hypertrophic scars are scarce. While Luo et al[3] demonstrated the efficacy of a mini-punch combined with photodynamic therapy for mandibular scars, our case highlights the potential of a similarly minimal approach as a standalone procedure for a delicate, cosmetically sensitive area such as the nose. The novelty of this report lies not in the invention of a new instrument, but in the specific application of this technique to a challenging anatomical site where conventional laser therapy had failed, and where surgical excision might carry higher risks of contour deformity or scar recurrence. By documenting the successful use of micro-punch matrix drilling in this location and achieving sustained improvement without combination therapy, this case serves as a hypothesis-generating starting point for future investigations.

The limitations of this case include the single-sample nature and short follow-up duration. Hypertrophic scars may recur or undergo late maturation beyond this time frame, and longer observation periods are typically required to adequately assess long-term stability. Additionally, while a 6-month in-person follow-up was completed with VSS assessment, standardized photographic documentation at this time point was unavailable due to logistical reasons beyond our control. Nevertheless, the 3-month postoperative photographs already demonstrated a significant flattening and near-complete color match, and the 6-month in-person examination confirmed sustained improvement. Future studies with extended photographic follow-up are warranted to further validate the long-term durability of this technique.

Based on this single case, potential candidates for the micro-punch technique may include patients with small, localized, recalcitrant hypertrophic scars that have failed to respond to conventional therapies, particularly in cosmetically sensitive areas such as the nose. Contraindications may include active infection, uncontrolled systemic diseases affecting wound healing, or a history of keloid formation, as the punctate wounds might theoretically trigger further abnormal scarring in susceptible individuals. However, these considerations are preliminary and require further validation.

The optimal punch diameter, density, depth, and the necessity of combination therapies (e.g., injections or energy-based devices) require further optimization through large-scale studies.

CONCLUSION

Micro-punch matrix drilling was associated with satisfactory improvement in this patient with a nasal hypertrophic scar. The procedure was well-tolerated, with rapid wound healing and no recurrence or adverse effects observed during the 6-month follow-up period. While this case demonstrates the potential utility of the micro-punch technique for selected hypertrophic scars resistant to conventional therapies, its broader applicability and long-term efficacy require further investigation in larger patient cohorts.