A case of crusted scabies with a bullous pemphigoid‐like eruption and nail involvement

Abstract

We report a case of a 71-year-old man infected at a nursing home who developed a bullous pemphigoid-like eruption with nail involvement. He was diagnosed by his family doctor as suffering from eczema and was treated with topical corticosteroids, then blisters started appearing. He was next diagnosed as suffering from bullous pemphigoid and treated with oral prednisolone, which worsened his condition. He was finally diagnosed as having crusted scabies with bullous pemphigoid-like eruptions and nail involvement at our clinic. He was then prescribed oral ivermectin (two doses of 12 mg ivermectin with a 1-week interval) and topical lindane (1%gamma-BHC in petrolatum) for scabies with 5% salicylic acid in plastibase as an additional treatment for the crusted lesions on his soles. He showed remarkable improvement in 2 weeks, and his nails showed complete recovery after 7 weeks of occlusive dressing treatment with 1%gamma-BHC. One and a half years later, the patient showed no sign of a recurrence of scabies. The histology of a blister taken from this patient was similar to that of bullous pemphigoid. Direct immunofluorescence showed immunoglobulin (Ig)G and C3 deposition at the dermoepidermal junction similar to that of bullous pemphigoid, but indirect immunofluorescence was negative. The bullous symptoms of this patient were considered to be due to the scabies, because the patient recovered completely after receiving treatment for scabies. Indirect immunofluorescent study is important to distinguish between scabies with blister formation and true bullous pemphigoid.

A case of bullous scabies misdiagnosed as acquired epidermolysis bullosa

“…[5][6][7][8] Thus, our case is the first to be acknowledged as attributable to severe phimosis. It is likely that the constricting phimotic ring may have been responsible for significant lymph stasis and the subsequent dilatation of the superficial lymphatic channels.…”

“…In the literature, linear immune deposits were found in eight of 31 cases of bullous scabies. [3][4][5][6][7][8][9][10] Bullous scabies can resemble autoimmune bullous diseases clinically, by light microscopy, and immunopathologically. 1 Several cases of bullous scabies have been reported as initially misdiagnosed and treated as bullous pemphigoid.…”

“…The age of onset ranges from puberty to 45 years; therefore the present patient represents the most belated instance ever described. [3][4][5][6][7][8] Acquired lymphangioma presents as asymptomatic, painful, burning or pruritic, thin-walled vesicles filled with a clear fluid. However, sometimes smooth and/or hyperkeratotic papulovesicles, papules, and/or nodules may occur, often leading to misdiagnoses such as herpetic infections, molluscum contagiosum and warts.…”

Crusted scabies

“…In such patients, an indirect immunofluorescent study is important to distinguish between scabies with blister formation and true bullous pemphigoid. [16] COMPLICATIONS COMPLICATIONS Crusted scabies is complicated by secondary bacterial infection by Staphylococcus aureus. They include impetigo, ecthyma, cellulitis and lymphangitis.…”

Guideline for the diagnosis and treatment of scabies in Japan (second edition)

“…In cases of nail scabies, mites are found below and/or above the nail plates. Although the efficacy of ivermectin against nail scabies has not been evaluated in preclinical studies, its ineffectiveness against nail scabies has been clinically reported 69,76 . Particularly in cases where mites are found above the nail plate, the drug is unlikely to reach the pathogen.…”