Koebner's phenomenon

phenomenon /phe·nom·e·non/ (fĕ-nom´ĕ-non) pl. phenom´ena   any sign or objective symptom; an observable occurrence or fact.

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booster phenomenon  on a tuberculin test, an initial false-negative result due to a diminished amnestic response, becoming positive on subsequent testing.

dawn phenomenon  the early morning increase in plasma glucose concentration and thus insulin requirement in patients with type 1 diabetes mellitus.

Koebner's phenomenon  a cutaneous response seen in certain dermatoses, manifested by the appearance on uninvolved skin of lesions typical of the skin disease at the site of trauma, on scars, or at points where articles of clothing produce pressure.

Marcus Gunn's pupillary phenomenon  with unilateral optic nerve or retinal disease, a difference between the pupillary reflexes of the two eyes; on the affected side there is abnormally slight contraction or even dilatation of the pupil when a light is shone in the eye.

no-reflow phenomenon  when cerebral blood flow is restored following prolonged global cerebral ischemia, there is initial hyperemia followed by a gradual decline in perfusion until there is almost no blood flow.

Somogyi phenomenon  a rebound phenomenon occurring in diabetes: overtreatment with insulin induces hypoglycemia, thus initiating hormone release; this stimulates lipolysis, gluconeogenesis, and glycogenolysis, which in turn cause rebound hyperglycemia and ketosis.

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Koebner's phenomenon

Isomorphic reaction The appearance of new lesions of a skin disease–in particular psoriasis, but also lichen planus or eczema at a site of trauma. See Id reaction, Psoriasis.