<\/span><\/h2>\nThe Koebner phenomenon describes the appearance of new skin lesions in areas of cutaneous<\/span> lesion on healthy skin. It is also known as the Kobner<\/span> freak<\/span> and isomorphic<\/span> reply.<\/p>\n\n<\/span>Linear lesions due to Koebner phenomenon in lichen planus<\/span><\/h5>\n<\/section>\n\n\n
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Linear lesions due to Koebner phenomenon in lichen planus<\/p>\n
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Linear lesions due to Koebner phenomenon in lichen planus<\/p>\n
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Linear lesions due to Koebner phenomenon in lichen planus<\/p>\n<\/p><\/div>\n<\/section>\n
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<\/span>What is the cause of the Koebner phenomenon?<\/span><\/h2>\nThe cause of the Koebner phenomenon is not clear. Current theories suggest that the Koebner phenomenon requires both epidermis<\/span> and dermis<\/span> be injured in the same place. The production of inflammatory<\/span> Substances and neuropeptides have been postulated as a non-specific first step, triggering a specific secondary disease process. The role of chemical messengers such as the nerve growth factor<\/span> (NGF) can be important.<\/p>\n\n
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<\/span>Under what conditions is the Koebner phenomenon observed?<\/span><\/h2>\nSkin conditions that regularly manifest Koebner phenomenon include psoriasis, vitiligo, and lichen planus. There have been reports of possible Koebner phenomena in many other conditions.<\/p>\n
A true Koebner response occurs at:<\/p>\n
\n- Psoriasis<\/li>\n
- Vitiligo<\/li>\n
- aura nevus<\/span><\/li>\n
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Lichen planus.<\/li>\n<\/ul>\n
A pseudo-Koebner response occurs with infections arising in an area of trauma<\/span>.<\/span><\/p>\n\n- Molluscum contagiosum<\/li>\n
- Warts<\/li>\n<\/ul>\n
Located<\/span> trauma can also lead to:<\/p>\n\n- \n
Beh\u04abet's disease and pgangrenous yoderma<\/span> (pathergy<\/span>)<\/li>\n- \nCancer<\/span>, e.g <\/span>Marjolin ulcer<\/span> arising in a long standing scar<\/span>\n<\/li>\n
- Darier's disease<\/li>\n
- Erythema<\/span> multiform<\/li>\n
- Granuloma<\/span> cancel<\/li>\n
- Hailey-Hailey disease<\/li>\n
- Kaposi sarcoma<\/span><\/li>\n
- Kyrle's disease<\/li>\n
- Lichen sclerosus<\/li>\n
- Morph<\/li>\n
- Necrobiosis<\/span> lipoidica<\/li>\n
- Pellagra<\/li>\n
- perforating folliculitis<\/li>\n
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Perforating reactive collagenosis.<\/li>\n<\/ul>\n