Dermatoscopic features of Koebner phenomenon in lichen planus on light and dark skin

Koebner phenomenon, also known as isomorphic response, is the appearance of active skin lesions in sites of epidermal injury. This manifestation is characteristic of different dermatological diseases, such as lichen planus, vitiligo and psoriasis. We present the case of a psoriatic patient who experienced Koebner phenomenon after Mantoux test, followed by eruption of generalized plaque psoriasis.

Download Full-text

Dermoscopic features of psoriasis, lichen planus, and pityriasis rosea in patients with skin type IV and darker attending the Regional Dermatology Training Centre in Northern Tanzania

Dermatology Practical & Conceptual ◽

10.5826/dpc.0901a11 ◽

2019 ◽

pp. 44-51 ◽

Cited By ~ 4

Author(s):

Maitseo Nwako-Mohamadi ◽

John Masenga ◽

David Mavura ◽

Ola Jahanpour ◽

Eva Mbwilo ◽

...

Keyword(s):

Lichen Planus ◽

Skin Diseases ◽

Skin Type ◽

Published Data ◽

Dark Skin ◽

Training Centre ◽

Pityriasis Rosea ◽

Type Iv ◽

Northern Tanzania ◽

White Scale

Background: Papulosquamous skin diseases can be challenging to diagnose, especially in dark skin. Dermoscopy is reported to be helpful, but few data are available on its use in skin type IV or darker. Objective: To describe dermoscopic features in plaque-type psoriasis (PP), lichen planus (LP), and pityriasis rosea (PR) patients attending the Regional Dermatology Training Centre in Moshi, Northern Tanzania, and to compare findings with published data. Methods: A descriptive cross-sectional study was conducted at a tertiary hospital from October 2016 to June 2017. Fifty-six patients with PP, 25 with LP, and 9 with PR were enrolled consecutively. Clinical diagnosis was confirmed with histopathology in 74.4%. Dermoscopic vascular and nonvascular features from 225 lesions were analyzed. Results: Of the 90 patients enrolled, 58.9% were male and the median age was 50 (interquartile range 32.8-60.0) years. In PP lesions, red dots were found in 64.2% and white scale in 45.5%. In LP lesions the background was violet in 45.5% and 58.2% revealed Wickham striae. In PR lesions a dull red background was found in 50.0%, white scale in 83.3%, but no vessels were detectable. Conclusion: Dermoscopy features in PP, LP, and PR in dark skin are mostly similar to those in light skin.

Download Full-text

Papulosquamous Disorders

10.2310/im.1103 ◽

2013 ◽

Author(s):

Elizabeth A Abel

Keyword(s):

Lichen Planus ◽

Seborrheic Dermatitis ◽

Primary Lesion ◽

Diagnosis And Treatment ◽

Pityriasis Rosea ◽

Large Plaque ◽

Pityriasis Lichenoides ◽

Koebner Phenomenon ◽

Pityriasis Rubra Pilaris ◽

Mucous Membranes

Papulosquamous disorders comprise a group of dermatoses that have distinct morphologic features. The characteristic primary lesion of these disorders is a papule, usually erythematous, that has a variable amount of scaling on the surface. Plaques or patches form through coalescence of the primary lesions. Some common papulosquamous dermatoses are pityriasis rosea, lichen planus, seborrheic dermatitis, tinea corporis, pityriasis rubra pilaris, psoriasis, and parapsoriasis. The etiology, diagnosis, and treatment of pityriasis rosea, lichen planus, and seborrheic dermatitis (including seborrheic dermatitis associated with AIDS) are discussed in this chapter. Also discussed are the diagnosis and treatment of pityriasis rubra, parapsoriasis (pityriasis lichenoides and small- and large-plaque parapsoriasis), and erythroderma. This chapter includes color photographs of the aforementioned dermatoses plus the Koebner phenomenon, lichen planus of the mucous membranes, and erythroderma in Sézary syndrome. This review contains 11 highly rendered figures and 79 references.

Download Full-text