ATYPICAL PRESENTATION OF SCABIETIC URTICARIAL VASCULITIS

Abstract

Introduction Pruritic rash with burrows is pathognomonic for scabies. Classic lesions are seen less frequently as the incidence has increased. Our patient presented with none of the classic findings of scabies and biopsy features consistent with urticarial vasculitis. Case Description 75-year old male presented with a generalized urticarial eruption for 1 month that burned and itched, and was accompanied by post-inflammatory hyperpigmentation. No new medications had been started. No family members had similar symptoms. Multiple urticarial plaques were noted with post-inflammatory changes without burrows. Dermatographism was present. Skin biopsy showed dense perivascular and superficial interstitial infiltrate, leukocytoclasis, and smudged small vessel walls. No mites or eggs were identified. No eosinophilia was present. Autoimmune work up and complement were normal. Treatment with Colchicine, Dapsone, Prednisone, and Hydroxychloroquine led to initial improvement but then relapse. When he was not improving, we sent him to dermatology again and they did not recommend any changes. As medications were changed, lesions again improved and then worsened. He called complaining of persistent lesions. When he was seen at that point, he had developed typical features of scabies and was treated with topical Permethrin and oral Ivermectin and rash completely subsided. After he improved, he was tapered off Dapsone without recurrence of his symptoms. Discussion Urticarial vasculitis is an uncommon presentation of scabies with frequently delayed diagnosis. This case serves as a reminder to reassess the diagnosis if the patient does not respond as expected to treatment and adds to the cases of scabies with atypical presentations.