Case 198. Scabies, Norwegian (generalized) (78 y-o F)
    Dirty gray-colored, scaled skin lesions, particularly in the head, extremities and trunk, seen in a poor farmer housewife    
Key words : 
Sarcoptes scabiei hominis, Norwegian scabies, nosocomial infection    
opportunistic infection
In the upper half of the body, gray-colored, oyster shell-like hyperkeratotic lesions are seen particularly on the head, ears, extremities and joint surfaces.   The lower half of the body also shows severe hyperkeratotic changes. Norwegian scabies is highly contagious. In this case, a delay of the diagnosis resulted in infection of numbers of nurses and residents.
In this severe infection, it is easy to identify the mites in the epidermis. Within the tunnels, adult females, eggs and feces are observed. The dermis is moderately inflamed.   Immunostaining for IgE shows deposition of IgE on the surface of the mite. Other immunoglobulins, including IgG, IgA, IgM and IgD, are negative. An allergic disease nature is suspected.
In the unstained skin scratch preparation after potassium hydroxide treatment, numbers of female mites with four paired legs are observed.