The pseudo-isomorphic phenomenon is seen in

Koebner response or the isomorphic response, attributed to Heinrich Kobner, is the appearance of skin lesions on lines of trauma. The Koebner phenomenon may result from either a linear exposure or irritation. Pseudokoebner phenomenon-Conditions demonstrating linear lesions after a linear exposure to a causative agent include molluscum contagiosum, was and toxicodendron dermatitis (dermatitis caused by a genus of plants including poison ivy). Was and molluscum contagiosum lesions can be spread in linear patterns by self-scratching ("auto-inoculation"). Toxicodendron dermatitis lesions are often linear from brushing up against the plant. True koebner phenomenon-Causes of the Koebner phenomenon that are secondary to scratching rather than an infective or chemical cause include vitiligo, psoriasis, lichen planus, lichen nitidus, pityriasis rubra pilaris, and keratosis follicularis Ref Harrison 20th edition pg 2111