Pseudo-isomorphic phenomenon – Dermatology MCQ

Pseudo-isomorphic phenomenon is characteristic of?
A. Vitiligo
B. Psoriasis
C. DLE
D. Plane warts

Correct answer : D. Plane warts

Heinrich Köbner

Pseudo-isomorphic phenomenon

• To learn about pseudo-isomorphic phenomenon, we first need to know what is isomorphic phenomenon.
• Isomorphic phenomenon (also known as Koebner phenomenon) is a phenomenon in which new skin lesions appear at the site of injury.
• It is named after Heinrich Köbner, a German dermatologist.
• Isomorphic phenomenon is seen in conditions like psoriasis,vitiligo and lichen planus.
• Pseudo-isomorphic phenomenon (Pseudo-Koebner phenomenon) is characterised by the appearance of similar skin lesions at the site of injury in infective lesions like plane warts and molluscum contagiosum.
• It occurs due to the spread of the infective agent (virus) to the new site.