INTRODUCTION
Keratoacantoma (KA) is a cutaneous neoplasm that is considered a low-grade squamous cell carcinoma. The tumor classically presents in sun-exposed areas as a solitary rapidly growing, dome-shaped, crateriform nodule with central keratinous plug. It often develops in fair-skinned individuals in the fth or sixth decade of life and involutes spontaneously in most cases. Pathergy is another widely recognized trigger for the development of this neoplasm. Numerous reports of KA arising in the setting of both iatrogenic and noniatrogenic trauma exist in the literature. In recent years, given the rise in number of treatment options for anti-aging and aesthetics, reports of KAs developing as a pathergic response to cosmetic procedures are increasing. There are currently ve reports of KA after laser resurfacing.1-5 We present a case of eruptive perioral KAs after facial resurfacing with full- eld Erbium:YAG 2940 nm ablative laser that, unlike prior reports, resolved with minimal intervention.
CASE REPORT
A 47-year-old woman (Fitzpatrick skin type II) was seen in the dermatology clinic for facial full- eld ablative erbium laser re- surfacing for photoaging. This was her rst laser treatment. She reported a personal history of melanoma on her right posterior upper arm but no history of non-melanoma skin cancers. Prior to the procedure, topical lidocaine 20% was applied to the treatment area for >30 minutes. Regional anesthesia with nerve blocks was placed with 1% lidocaine with epinephrine; a total of 6 cc was administered. Oxycodone 5 mg was given for prophylactic pain control. The face was prepped three times with alcohol. She underwent a full-face treatment with a Erbium:Yag 2940 nm fully ablative laser (Contour TRL, Sciton, Inc., Palo Alto, CA). The depth of ablation used on the upper and lower cutaneous lips was 500 microns without coagulation. She tolerated the procedure well with significant, though expected, post-procedure epidermal disruption (Figure 1). For comfort, cool water soaked gauze and a cold-air cooling device (Zimmer Medizin Systems, Irvine, CA) were utilized. A post care regimen included a sevenday course of Cephalexin 500mg three times daily with Elta laser balm and acetic acid soaks twice daily. Four weeks later, the patient returned to clinic with three new 2-3 mm, skin-colored, verrucous papules on the right inferior vermilion lip, left inferior vermilion lip, and left superior vermilion lip (Figure 2). Initially, these were clinically regarded as verruca vulgaris. Punch biopsy of the two lower lip lesions revealed atypical squamous proliferations, most consistent with eruptive keratoacanthomas (Figures 3 & 4). Of note, no perineural invasion was identi ed.Two of the lesions were treated with liquid nitrogen without improvement.The lesions were clinically monitored and patient was advised to applyTazorac 0.1% cream daily.The lesions had improved by the time of the two week follow up, and had completely resolved within 4-6 weeks.
DISCUSSION
Numerous reports of KA arising in the setting of trauma exist in the literature. Cases have been reported post motor vehicle accidents, burns, thorn injuries, dog scratches, and arthropod stings.3 Though unpublished, our practice cared for a patient that developed three biopsy-proven KAs in a linear lower leg injury after falling on ice (Figure 5); interestingly, her sister had also developed similar traumatic KAs. Beyond these accidental and incidental exposures, medical and cosmetic procedures are
