A case of crusted scabies combined with bullous scabies.

Scabies is a contagious skin disease that causes extremely itching. It is a parasitic disease caused by the mite Sarcoptes scabiei and characterized by polymorphous lesions. Vesicular and bullous lesions in cases of scabies are rather rare. Bullous scabies has a pemphigoid presentation. Crusted scabies, also known as Norwegian scabies, is a rare and severe form of the disease. The large number of mites present in and on the skin cause scabies to be highly contagious. The present study reports a case of crusted scabies combined with bullous scabies, the clinical and histopathological manifestations of which mimicked those of bullous pemphigoid. Direct and indirect immunofluorescence test results were negative. Bullae recurred and persisted despite systemic corticosteroids and antihistamine medication. The patient was successfully treated with 10% sulfur cream and remained free of recurrence during the 12 months of follow-up. Differential diagnosis with bullous pemphigoid and the mechanism of formation of bullae are also discussed.