Bullous Scabies

Abstract

Scabies is a common contagious cutaneous disease and usually affects the young, characterized by polymorphous lesions that may present as burrows, pruritic papules, and inflammatory nodules. Bullous scabies (BS) is its rather rare subtype, mimicking bullous pemphigoid. We report a 15-year-old Chinese boy presenting with 1-month history of pruritic bullae on his penile skin, showing poor response to both topical steroids and systemic antihistamines, but cured by sulfur ointment alone. No recurrence occurred in the 5 years of follow-up. We also reviewed the published cases. Up to date, 44 cases, including the present, have been reported. Of them, 30 were male and 14 were female. The age range was from 1 to 89 years old, with a median age of 70.6 years. The bullous lesions may involve the arms, legs, trunk, genitals, feet, buttocks, thighs, neck, inguinal folds, and may even be generalized. Trunk and extremities are the most common involved locations. Facial or mucosa involvement had never been reported. The histological findings present as a subepidermal split with variable inflammatory infiltrate predominantly neutrophils, and eosinophilic spongiosis, or both. Eighteen of 32 patients showed positive deposition of linear-granular IgG or complement 3 alone or in various combinations, and five of 24 patients revealed circulating IgG. All the 40 cases with therapeutic details were cured by antiscabietic remedy. BS always involves the trunk and extremities. It has a predilection for elderlies and males. The treatments for BS are similar to those of classical scabies.

Case Report: Bullous Scabies in Two Children below 10 Years

“…The rarity of the report of BS in children may be because it is not properly diagnosed or neglected as a disease by the doctors when the child was referred for consultation. As five cases of BS, 1,7,8 including the present two, have been diagnosed by the present author's group in less than 8 years, we support the opinions that BS may have been largely misdiagnosed or neglected in China. 1 The mechanisms of bullous formation remain unknown, although deposition of complement three or various immunoglobulins alone or in various combinations, or circulating IgG were detected in some of the cases.…”

“…As five cases of BS, 1,7,8 including the present two, have been diagnosed by the present author's group in less than 8 years, we support the opinions that BS may have been largely misdiagnosed or neglected in China. 1 The mechanisms of bullous formation remain unknown, although deposition of complement three or various immunoglobulins alone or in various combinations, or circulating IgG were detected in some of the cases. 1 The possible pathogenesis for BS is considered including autoeczematization, superinfection, the direct injury or secretion of lytic enzymes by the scabies mites, and cross-reactivity of scabies protein with basement membrane zone antigens.…”

“…Although well-defined diagnostic criteria for BS do not exist at present, based on our prior described practical approach for diagnosis of BS, 1 and the excellent response to medication, the bullous lesions in both patients can be considered to be caused by scabies and can be diagnosed as BS rather than any other bullous diseases such as bullous impetigo. The previous review demonstrated that BS commonly afflicts the elderly with a median age of 70 years with a male predilection, 1 and only four were younger than 10 years. [2][3][4][5] However, Boralevi et al 6 reported that 6.2% patients of scabies (12 out of 193) below 15 years presented blisters, implying that BS might not be so rare in children.…”

Serological investigation of bullous scabies and review of the published work

“…Forty-four cases of BS have been reported until 2016. 2 Among them, 18 of 32 cases were positive in direct IF and five of 29 cases were positive in indirect IF. Dermatologists should quickly make a diagnosis of BS to prevent outbreaks of scabies.…”

“…1 Bullous scabies is a rare subtype of scabies showing bullous lesions. 2 It is often difficult to distinguish BS from BP, 3 which causes the delay of diagnosis. Autoantibodies and autoantigens in BS are unclear.…”