Abstract
Diagnosis: Facial porokeratosis. Microscopic findings and clinical course Histologic examination of the biopsy specimen showed a focal invagination of the epidermis with a column of parakeratotic cells in the horny layer (cornoid lamella). Granular layer underlying the lamella was absent, and continuous epidermis was thinned. Superficial dermis showed a sparse lymphocytic infiltrate without solar elastosis changes (Figure 2 and 3). Tretinoin, 0.025%, was applied once a day topically to the lesions with partial improvement after 3 months. Sun protection was also recommended. View LargeDownload Figure 2. View LargeDownload Figure 3. Discussion Porokeratosis is an uncommon and heterogeneous group of keratinization disorders the main histologic feature of which is the presence of the cornoid lamella.1 Porokeratosis of Mibelli was first described in 1893, and since then, various clinical forms have been described. The classic form of Mibelli and disseminated superficial actinic porokeratosis (DSAP) are the 2 most common forms.2 This disease follows an autosomal dominant pattern of inheritance, although sporadic cases have been reported.3 Facial porokeratosis is a clinical variant that predominantly affects young women, without lesions in other locations. It has been reported that 15% of DSAPs affect the facial area, although patients with DSAP also have lesions in other locations.4 To our knowledge, only 39 cases of facial porokeratosis have been reported.5 Lesions are asymptomatic or slightly pruritic, regardless of the location or the clinical settings.2-9 Clinically, they appear as annular lesions surrounded by a raised, sharply marginated keratotic edge, predominantly affecting the nasal and perinasal areas.6 Cornoid lamella is the histologic hallmark of all clinical variants of porokeratosis, but it can also be found as an incidental finding in inflammatory, hyperplastic, and neoplastic skin processes.1 In these circumstances, finding atypia in the basal keratinocytes helps the differential diagnosis of actinic keratosis. No atypias were observed in our case. The pathogenesis of this disease is unknown. Most authors believe that there is an alteration of keratinization that emerges from a mutated clone of epidermal cells. Various triggering factors have been described such as sun exposure (especially in the DSAP), trauma, and immunosuppression.7 Although isolated cases of evolution into squamous cell carcinoma, Bowen disease, or basal cell carcinoma have been reported, malignant degeneration has not been observed in any case of facial porokeratosis alone.8 Multiple treatments have been used: topical therapies (keratolytic agents, 5-fluorouracil, and imiquimod), ablative therapies (cryotherapy, carbon dioxide laser, and dermabrasion), oral retinoids, and photodynamic therapy, with different outcomes.9 None of these treatments has been universally successful, and at present there is no consensus about the optimum approach for this condition. Return to Quiz Case. References 1. Vergara G, Ba ñuls J, Botella R, Silvestre JF, Belinch ón I, Betlloch I. Porokeratosis of the lower lip. Eur J Dermatol. 2002;12(5):500-50212370146PubMedGoogle Scholar 2. Carranza DC, Haley JC, Chiu M. Facial porokeratosis. Skinmed. 2008;7(1):51-5218174807PubMedGoogle ScholarCrossref 3. Ferahbas A, Utas S, Koc C, Canoz O. A case of facial porokeratosis. J Eur Acad Dermatol Venereol. 2006;20(3):355-35616503912PubMedGoogle ScholarCrossref 4. Chernosky ME, Freeman RG. Disseminated superficial actinic porokeratosis (DSAP). Arch Dermatol. 1967;96(6):611-6244864722PubMedGoogle ScholarCrossref 5. Gutierrez EL, Galarza C, Ramos W, et al. Facial porokeratosis: A series of six patients. Australas J Dermatol. 2010;51(3):191-19420695858PubMedGoogle ScholarCrossref 6. Sharquie KE, Al-Baghdady BA. Solar facial porokeratosis. J Dermatol. 2003;30(3):216-22112692358PubMedGoogle Scholar 7. Chaudhary RG, Bilimoria F, Katare SK. Large annular plaque with central atrophy on nose. Indian J Dermatol Venereol Leprol. 2009;75(5):552-55319736462PubMedGoogle ScholarCrossref 8. Wang NS, Gruson LM, Kamino H. Facial follicular porokeratosis: a case report. Am J Dermatopathol. 2010;32(7):720-72220559115PubMedGoogle Scholar 9. Robati RM, Rahmati-Roodsari M, Ayatollahi A, Hejazi S. Facial and bilateral acral porokeratosis with nail dystrophy: A case report. Dermatol Online J. 2011;17(1):521272496PubMedGoogle Scholar
Journal
Archives of Dermatology
– American Medical Association
Published: Sep 1, 2011
Keywords: porokeratosis
