Wound healing is impaired in both psoriasis and multiple sclerosis, raising the prospect that a better understanding of the process could improve our understanding of the pathophysiology of these two chronic conditions and generate targets for treating them … The two conditions share a number of characteristics … For example, both diseases demonstrate slight itching, symmetry of the lesions, exacerbation after stopping corticosteroid treatment, and the Koebner phenomenon – provocation of the condition by stress … The Koebner phenomenon (isomorphic response) was first described in 1876 by the German dermatologist Heinrich Koebner who noted that patients developed psoriasis at sites of excoriations, horse bites, and tattoos … Koebner famously saw a psoriatic plaque develop on the skin of a farmer where his horse … read more