Treatment of a Symptomatic Dermatofibroma With Fractionated Carbon Dioxide Laser and Topical Corticosteroids

Dermatofibromas are common benign tumors of the skin. They are often cosmetically undesirable and typically asymptomatic but may become tender or pruritic, prompting patients to seek treatment. Common treatments for dermatofibromas include cryotherapy, surgical excision, and intralesional steroid injections, which may result in incomplete resolution, scarring, atrophy, and hypopigmentation. More recently, the non-ablative pulsed dye laser (PDL) has been described as an alternative therapy with variable efficacy.^1,2 Adverse effects associated with PDL treatment of dermatofibromas include post-inflammatory hyperpigmentation, which resolved within 6 months in one study.² Unlike PDL, fractionated CO₂ laser is an ablative modality.³ Potential adverse effects include pain, bleeding, scarring, and pigmentary alteration. Fractionated CO₂ laser has been used for the treatment of various epidermal and dermal lesions,³ but only one other report has described its efficacy in treating dermatofibromas. ⁴ The authors presented a patient with multiple facial dermatofibromas who underwent CO₂ laser treatment (settings not specified) with minimal scarring and no recurrence at 8-month follow-up.⁴

A 47-year-old African American woman presented with a 1 cm raised dermatofibroma on her left thigh (Figure 1). It had been present for 4 years, but because it was becoming larger and increasingly pruritic, she expressed interest in treatment. We treated the dermatofibroma with the DEKA SmartXide DOT HP fractional CO₂ laser (DEKA Medical, San Francisco, CA) three times approximately 5 weeks apart (Table 1). We reduced the laser spot size as the lesion size decreased. After the first laser treatment, she also applied fluocinonide 0.05% ointment to the treated site twice daily for 9 weeks. Due to improvement in the lesion, she was tapered to triamcinolone 0.1% ointment twice daily for an additional 4 weeks. By one month after the final laser treatment, she noted complete flattening of the lesion and resolution of her pruritus. At her 7-month follow-up appointment, mild peri-lesional post-inflammatory hyperpigmentation was seen, but there was no evidence of recurrence of the dermatofibroma (Figure 2). The patient tolerated her treatment well and was very pleased with the outcome.

The mechanism by which dermatofibromas respond to fractionated CO₂ laser and corticosteroid therapy has not been fully elucidated. Laser-induced damage to the collagenous stroma of the dermatofibroma may facilitate reduction in lesion size and volume.² In addition, corticosteroids decrease collagen synthesis by suppressing the inflammatory process and inhibiting fibroblast proliferation through reducing pro-fibrotic growth mediators, specifically transforming growth factor-beta and insulin like growth factor-1.⁵ Thus, the microscopic channels created by the fractionated CO₂ laser may have enhanced topical corticosteroid delivery to the dermis to achieve a synergistic anti-fibrotic effect in our patient. The authors of a recent case series describing same-session ablative fractional laser therapy and topical corticosteroid application for hypertrophic scars also proposed a similar mechanism.⁶