Linear porokeratosis: Treatment with the carbon dioxide laser James H. Barnett, M.D. Milwaukee, WI A patient with a lifelong linear porokeratosis was treated with a carbon dioxide laser. The laser was successful in removing the patient's hyperkeratotic plantar lesion. No recurrence has been noted in a &month follow-up visit. This report demonstrates another dermatologic condition that can be treated successfully with the CO2 laser. (J AM ACAD DERMATOL14:902-904, 1986.)
The existence of linear porokeratosis has been well recognized, m Porokeratotic lesions have a unique clinical appearance with a peripheral hyperkeratotic furrow. Histologically these lesions have a characteristic morphologic feature known as the cornoid lamella. Porokeratotic lesions are progressive in nature and have a tendency to become malignant neoplasms. Treatments of this condition are numerous and variable in their outcome. To m y k n o w l e d g e this is the first porokeratotic condition successfully treated with a carbon dioxide laser.
CASE REPORT A 23-year-old man with a lifelong history of a "scaly rash" had been treated by various physicians with a wide variety of treatment moralities, including cryosurgery, electrosurgery, and keratolytics, all of which yielded only temporary results. The patient stated that the lesion was "present at birth and that there was no family history of similar conditions." Sun exposure had no effect on his skin condition. The patient noted that at the plantar aspect of the base of the first and second toes of his right foot, a growth was progressively enlarging and was occasionally painful. The findings of a cutaneous physical examination were notable because of a linear eruption that extended From the Department of Dermatology and Laser Surgery, St. Mary's Hospital. Correspondence to: Dr. James H. Barnett, 2040 W. Wisconsin Ave., Milwaukee, Wl 53233.
Fig. 1. Right foot prior to treatment; verrucous plaques with peripheral longitudinal furrow. from the proximal portion of his right thigh laterally to the lower portion of his leg and involved the heel, the dorsal aspect of his fourth and fifth toes, and the medial aspect of the plantar surface. The right lateral portions
Volume 14 Number 5, Part 2 May, 1986
Fig. 2. Biopsy specimen showing a hyperkeratotic epidermis with a parakeratotic column. No malignant or viral changes are noted. (Hematoxylin-eosin stain; x 400). of the penile shaft and glans were similarly involved. Morphologic study of all areas, aside from the plantar aspect of the foot, revealed discrete and confluent erythematous atrophic plaques ranging in size from 0.2 to 10 cm. All lesions had a peripheral longitudinal furrow, The plantar lesions exhibited the same characteristics but were significantly hyperkeratotic; a lesion present between the first and second digit was very tender to palpation (Fig. 1). Because of failures of other treatment modalities, it was decided to use a CO2 laser to excise the plantar lesion at the first and second foot webs. This area was used not only as a test area but also to rule out malignant degeneration. The Sharplan Model 743 COz laser was used on an area anesthetized locally with 2% xylocaine. The painful verrucous lesion was excised with 5 watts set at a continuous mode. The beam point size was 0.17 mm in diameter, with a resultant power density of 2,941 watts/era 2. Intraoperative bleeding was less than 0.5 ml, and postoperative complaints of pain were minimal. Histologic study of the excised lesion revealed massive hyperkeratosis with many columns of parakeratotic cells overlying dyskeratotic epidermal cells. No malig-
Fig. 3. Web between first and second toes of the right foot, 6 months after laser treatments. Porokeratotic lesion did not recur. nant nor viral changes were noted (Fig. 2). These findings were characteristic of hyperkeratotie porokeratosis, thus confirming the diagnosis of linear porokeratosis. The surgical site was kept dry and healed by secondary intention within 6 weeks. An area on the lateral aspect of his right heel where a 4-ram punch biopsy and subsequent electrodesiceation had been performed required 8 weeks to reepithelialize. At a 6-month follow-up (Fig. 3), there was no local recurrence, pain, or tenderness on palpation. The patient refused a biopsy of the laser-treated area. He believed that the area had healed faster than when previously treated with electrodesiccation. He also thought that the postoperative pain was less. DISCUSSION Porokeratotic lesions have many clinical presentations, including the classic Mibelli, or solitary plaque type~; zosteriform or linear lesionsZ-~; the disseminated superficial actinic variety3'4; by-
Journal of the American Academy of Dermatology
perkeratotic lesions3; ulcerative lesionsS; and porokeratosis plantaris discreta: The zosteriform, or linear porokeratosis, lesions have been well described previously ~'2 and should be differentiated from other hyperkeratotic lesions, such as verrucous epidermal nevus, lichen striatus, linear psoriasis, linear lichen planus, and verruca vulgaris) '7 The porokeratotic lesions have a tendency to develop into malignancy. Squamous cell carcinoma8"9 is the most common form of carcinoma found within these porokeratotic lesions, but basal cell carcinoma9 and Bowen's disease have also been reported.l~ Intervention in these conditions may be necessary, since the lesions are progressive in nature, can be painful, as in my patient, and have a propensity toward malignant degeneration. Treatment regimens for porokeratotic lesions have been medical as well as surgical. The former group includes keratolytics, topical 5-fluorouracil, ~ and etretihate. s Surgical approaches have included cryosurgery, electrocautery, and e x c i s i o n . 6,9-~x In this case of linear porokeratosis, because of previous treatment failures, progressive growth, symptoms of pain, and the wish to rule out malignancy, as well as the advantages of laser surgery, which have been discussed in depth elsewhere,~2:3 it was thought that a treatment with the CO2 laser should be performed. Six months postoperatively, the laser surgery was effective in removing the lesion and eliminating pain. The laser site, in comparison with an area on the heel where biopsy and electrodesiccation were done, reepithelialized in 6 weeks, whereas the electrodesiccation site took 8 weeks to heal. This difference is interesting because most investigators believe that laser surgery, since it is similar to a bum injury, prolongs the healing response.14 Clinically, the patient believed that postoperative pain and time required for healing were significantly less in comparison with surgical treatments he had previously undergone. Laser surgery has come of age, with an increasing number of conditions indicated for its usage. This list includes, in part, a myriad of vascular lesions such as port-wine stain, ~-~'z5:6verruca vulgaris, ~3granuloma faciale, 17angiosarcomas, zs balanitis xerotica obliterans, j9 and tattoos. 2~ We can
now add porokeratotic lesions to this ever-growing list, since the results were excellent, as demonstrated in this case. However, only time and the treatment of other individuals with porokeratoses will determine the overall effectiveness of the CO2 laser in the treatment of this unique lesion. REFERENCES 1. Rahbari I, Cordero AA, Mehregan AH: Linear porokeratosis: A distinctive clinical variety of porokeratosis of Mibelli. Arch DermatoI 109-526-528, 1974. 2. Goldner R: Zosteriform porokeratosis of Mibelli. Arch Dermatol 104:425-427, 1971. 3. Mikhail GR, Wertheimer b-W: Clinical variants of porokeratosis. Arch Dermatol 98:124-131, 1968. 4. Chemosky ME, Freeman RG: Disseminated superficial actinic porokeratosis. Arch Dermatol 96:611-624, 1967. 5. Razack EM, Natarajan M: Ulcerative systematized porokeratosis. Arch Dermatol 113:1583-1584, 1977. 6. Mandojana RM, Katz R, Rodman OG: Porokeratosis plantaris discreta. J AM ACAD DERMATOL 10:679-682, 1984. 7. Witkowski JA, Parish LC: Linear porokeratosis presenting as mosaic plantar warts. Int J Dermatol 21:4041, 1982. 8. Scott OLS: Porokeratosis of Mibelli with squamous cell carcinoma. Br J Dermatol 109(suppl 24):74, 1983. 9. Cost DF, Abdel-Aziz AHM: Epithelioma arising in porokeratosis of Mibelli. Br J Plast Surg 25:318-328, 1972. 10. Coskey RJ, Mehregan A: Bowen's disease associated with porokeratosis of Mibelli. Arch Dermatol 111:14801481, 1975. 11. Gon~alves JCA: Fluorouracil ointment treatment of 13orokeratosis of Mibelli. Arch Demaatol 108:131-132, 1973. 12. Arndt KA, Noe JM: Lasers in dermatology. Arch Dermatol 118:293-295, 1982. 13. MeBumey El, Rosen DA: Carbon dioxide laser treatment of verrucae vulgares. J Dermatol Surg Oncol 10:45-48, 1984. 14. Fidler JP: Technique of laser bum surgery, in Goldman L, editor: The biomedical laser: Technology and clinical applications. New York, 1981, Springer-Verlag New York, Inc., pp. 199-218. 15. Apfelberg DB, Maser MR, Lash H: Extended clinical use of the argon laser for cutaneous lesions. Arch Dermatol 115:719-721, 1979. 16. Goldman L, Dreffcr R: Laser treatment of extensive mixed cavernous and port-wine stains. Arch Dermatol 113:504-505, 1977. 17. Apfelberg DI3, Drucker D, Maser MR, et al: Granuloma faciale. Arch Dermatol 119:573-576, 1983. 18. Goldman L, Naprstek Z, Johnson J: Laser surgery of digital angiosarcoma. Cancer 39:1739-1742, 1977. 19. Rosemberg SK, Jacobs H: Continuous-wave carbon dioxide treatment of balanitis xerotica obliterans. Urology 19:539-541, 1982. 20. Bailin PL, Ratz JL, Levine HL: Removal of tattoos by CO2 laser. J Dermatol Surg Oneol 6:997-1001, 1980.