Psoriasis sparing the lower limb with postpoliomyelitis residual paralysis

Funding sources: none. Conflicts of interest: T.‐F.T. has conducted clinical trials or received honoraria for serving as a consultant for Wyeth Pharmaceuticals (now Pfizer Inc.), Novartis International AG and Janssen‐Cilag Pharmaceuticals and received speaking fees from Abbott (now Abbovie). T.‐S.W. has no conflicts of interest to declare. Dear Editor, A 67‐year‐old man was seen in our clinic for aggravation of his psoriasis in recent months without a definitive cause. He had suffered from relatively stable plaque‐type psoriasis covering only about 1% of body surface area for more than 10 years; this was controlled with topical corticosteroids and calcipotriol. He was otherwise healthy except for poliomyelitis, which had affected his left lower limb since childhood. No obvious Koebner phenomenon was present and the lesions were only slightly pruritic. He was not taking any oral medication known to aggravate psoriasis. On inspection, he had typical small psoriatic plaques covering 4·5% of the body surface area with Psoriasis Area and Severity Index (PASI) of 6·7. On the trunk and upper limbs, his psoriatic lesions were symmetrically distributed, but the left lower limb was conspicuously free of lesions compared with the right lower limb (Fig. 1a, b). The lesions gradually resolved after treatment with oral methotrexate and acitretin in addition to topical calcipotriol.