Lichen planus pigmentosus and ashy dermatosis: a clinical, dermoscopic and histopathological comparison
Keywords:
Ashy dermatosis, lichen planus pigmentosus, dermoscopyAbstract
Background Lichen planus pigmentosus (LPP) and ashy dermatosis (AD) are disorders of hyperpigmentation and differentiation between two can be difficult. They can be close mimickers. Earlier they were considered the same entity but over time various authors enlisted a few clinical and histopathological differences between the two. In this review, we would add the additional dermoscopic differences and review the clinical and histopathological differences between these two confusing entities. Aim To differentiate between lichen planus pigmentosus and ashy dermatosis on the basis of clinical, dermoscopic and histopathological features. Methods We selected ten patients of newly diagnosed lichen planus pigmentosus and ten of ashy dermatosis presenting to dermatology OPD. Clinical examination, dermoscopy and punch biopsy were performed in each case. Results Out of the 20 patients who were included in this study, 10 were diagnosed with lichen planus pigmentosus and 10 with ashy dermatosis. 80% patients presented with pruritus in LPP and all patients were asymptomatic in AD. In LPP, most common pattern was diffuse where on dermoscopic examination, granules were seen arranged in a hem like pattern. In AD, pigment was seen present in a curvilinear fashion. Conclusion Differentiation between lichen planus pigmentosus and ashy dermatosis can be a daunting task. Dermoscopy is a useful and non-invasive modality that can be of immense help.References
Bhutani LK, Bedi TR, Pandhi RK, Nayak NC. Lichen planus pigmentosus. Dermatologica 1974; 149: 43-50.
Novick NL, Phelps R. Erythema dyschromicum perstans. Int J Dermatol 1985; 24: 630-3.
Ramirez CO. Los cenicientos: Problema clinica. Proceedings of the first Central American Congress of Dermatology. 1957: 122-30.
Vega ME, Waxtein L, Arenas R et al. Ashy dermatosis and lichen planus pigmentosus: a clinicopathologic study of 31 cases. Int J Dermatol 1992; 31: 90-4
Ghosh A, Coondoo A. Lichen planus pigmentosus: The controversial consensus. Indian J Dermatol 2016; 61: 482-6
Correa MC, Memije EV, Vargas-Alarcón G, Guzmán RA, Rosetti F, Acuña-Alonzo V, Martínez-Rodríguez N, Granados J. HLA-DR association with the genetic susceptibility to develop ashy dermatosis in Mexican Mestizo patients. J Am Acad Dermatol 2007; 56(4): 617-20.
Vásquez-Ochoa LA, Isaza-Guzmán DM, Orozco-Mora B, Restrepo-Molina R, Trujillo-Perez J, Tapia FJ. Immunopathologic study of erythema dyschromicum perstans (ashy dermatosis).Int J Dermatol 2006; 45(8): 937-41.
Jablonska S. Ingestion of ammonium nitrate as a possible cause of erythema dyschromicum perstans (ashy dermatosis) Dermatologica 1975; 150: 287-91.
Lambert WC, Schwartz RA, Hamilton GB. Erythema dyschromicum perstans. Cutis 1986; 37:42-4.
Zenorola P, Bisceglia M, Lomuto M. Ashy dermatosis associated with cobalt allergy. Contact Dermatitis 1994; 31: 53-4.
Penagos H, Jimenez V, Fallas V, O’Malley M, Maibach HI. Chlorothalonil, a possible cause of erythema dyschromicum perstans (ashy dermatitis) Contact Dermatitis 1996; 35: 214-8.
Chua S, Chan MM, Lee HY. Ashy dermatosis (erythema dyschromicum perstans) induced by omeprazole: a report of three cases.Int J Dermatol 2015; 54(10): 435-6.
Srivastava N, Solanki LS, Chand S, Garbyal RS, Singh S. Ashy dermatosis-like pigmentation due to ethambutol. Indian J Dermatol Venerol Leprol 2008; 74(3): 281-2.
Laskaris GC, Papavasiliou SS, Bovopoulou OD, Nicolis GD. Lichen planus pigmentosus of the oral mucosa: a rare clinical variety. Dermatologica 1981; 162: 61-3.
Kanwar AJ, Dogra S, Handa S, Parsad D, Radotra BD. A study of 124 Indian patients with lichen planus pigmentosus. Clin Exp Dermatol 2003; 28(5): 481-5.
Khopkar U. Dermoscopy and Trichoscopy in diseases of the Brown skin.Atlas and short text. 2012. Jaypee Brothers Medical Publishers Ltd. New Delhi.
Cutrì FT, Ruocco E, Pettinato G, Ciancia G. Lichen planus pigmentosus-like ashy dermatosis. Dermatol Reports 2011; 3(3): 46.
Convit J, Piquer-Martin J. Erythema dyschromicum perstans. Int J Dermatol 1989; 28: 168-9.
Pinkus H. Lichenoid tissue reactions: a speculative review of the clinical spectrum of epidermal basal cell damage with special reference to erythema dyschromicum perstans. Arch Dermatol 1973; 107: 840-6
