Sean Klepper M.D.
Artur Zembowicz M.D....
Also known as: crusted scabies
- Caused by the mite Sarcoptes scabiei var. hominis
- Transmitted by person-to-person contact or sometimes fomites
- This type of scabies infestation affects immunocompromised or hospitalized patients, and is characterized by the presence of numerous mites, in contrast to the small number seen in typical scabies.
- Intensely pruritic linear burrows with a predilection for the interdigital webs, flexural surfaces of joints and genitalia
- Norwegian scabies shows hyperkeratotic or psoriasiform papules or plaques or sometimes diffuse erythroderma.
- Irregular acanthosis
- Focal spongiosis
- The burrow may be seen as a space within or subjacent to the stratum corneum.
- The female mite or her eggs may be seen within the burrow. Levels may be sometimes be required to visualize the diagnositic mite or eggs, although they are much more numerous and likely to be seen in Norwegian scabies than in a typical scabies infestation.
- Superficial and deep perivascular lymphohistiocytic and eosinophilic infiltrate (A nodular infiltrate with eosinophils is not seen in psoriasiform lesions of other etiologies.)