Scabietic vasculitis: Report of 2 cases.

BACKGROUND: The infectious causes of cutaneous vasculitis are well known and include streptococcal infections among others. Cases resulting from parasitic infection are less frequent. Scabies, which is currently on the increase, has only been reported in a few isolated cases. Herein, we report two noteworthy cases of profuse scabies complicated by cutaneous vasculitis. PATIENTS AND METHODS: Case 1: a 90-year-old woman, residing in a nursing home, was admitted to our dermatology department complaining of pruritus, present for one month, predominantly on the inside of the thighs and on the buttocks, associated with purpuric lesions on the lower limbs. A skin biopsy revealed leukocytoclastic vasculitis. A diagnosis of scabies was based on severe pruritus and hypereosinophilia and was confirmed by microscopic examination of the parasitology sample and the skin biopsy sample. Despite thorough investigation, no other cause of vasculitis could be found. Complete regression of the skin lesions was achieved with scabies treatment only, without any specific treatment for the vasculitis. Case 2: a 74-year-old man, living in a nursing home, was hospitalized for purpuric papules on the lower limbs, present for one month. Physical examination revealed linear patterns in the interdigital spaces associated with scabies evident on dermoscopic examination. The skin biopsy revealed signs of vasculitis. As in our first case, no aetiology of vasculitis was found and a favorable outcome was achieved by means of scabies treatment alone with no specific treatment for vasculitis. DISCUSSION: Both of our patients presented scabies and vasculitis. In view of the absence of other causes of vasculitis and of the complete regression of lesions due to vasculitis without recurrence achieved with the scabies treatment alone, a diagnosis was made of scabietic vasculitis, probably as a result of cutaneous hypersensitivity reaction to humeral mediators.