Scabies

Background

Scabies is an infection with the mite Sarcoptes scabiei var hominis. It is a very common disease and highly contagious, usually contracted under conditions of crowding, poor hygiene, and sexual contact. The classic symptoms is pruritis or itching affecting any part of the body but usually the hands and genital areas. The lesions are macular, papular, vesicles, scaly plaques, nodules, and oozing patches. The lesions may be particularly widespread in infants, affecting the head and face as well.

GROSS APPEARANCE/CLINICAL VARIANTS CHARACTERIZATION

General

VARIANTS

Norwegian scabies
Cutis 1995;11:18-19

Fulminant and highly infectious form of the disease caused by an immunocompromised state
May be present in AIDS patients

Thickened plaques with hyperkeratosis mainly affecting acral surfaces, usually not pruritic

HISTOLOGICAL TYPES CHARACTERIZATION

General
Superficial and deep mixed inflammatory cell infiltrate with lymphocytes, eosinophils, plasma cells, and histiocytes

Epidermis may show eosinophilic spongiosis with hyperplasia or parakeratosis

The female mite, feces (scybula), egg, and larvae may be present in the stratum corneum

VARIANTS

CD30 POSITIVE CELLS

CD30 antigen expression in cutaneous inflammatory infiltrates of scabies: a dynamic immunophenotypic pattern that should be distinguished from lymphomatoid papulosis.

Gallardo F, Toll A, Pujol RM; Carlos Barranco.

Department of Dermatology, Hospital del Mar, IMAS, Barcelona, Spain Department of Dermatology, Pathology, Hospital del Mar, IMAS, Barcelona, Spain.
J Cutan Pathol 2002 Jul;29(6):368-73 Abstract quote
Background: Expression of CD30 antigen is a distinct marker of lymphocyte activation that was originally described in the Reed-Sternberg cells of Hodgkin's disease. The observation of CD30+ cells has been considered a diagnostic feature of cutaneous CD30 lymphoid proliferations. However, CD30 expression has also been reported in some cutaneous benign inflammatory infiltrates.

Methods: Eleven skin biopsies from patients with scabies were double-blindly and retrospectively analysed. A panel of histopathological parameters and immunophenotypic expression of CD4, CD8, CD30 and S-100 antigens was studied. CD30 and S-100 antigens expression were related to clinical features.

Results: Large CD30+ cells were demonstrated in eight (8/11) biopsies, corresponding to patients with long-standing lesions (3 months or longer). However, no expression of the CD30 antigen was observed in all biopsy specimens (3/11) corresponding to early lesions (2 months or less). The presence of S-100 positive cells in the papillary dermis was an almost constant feature.

Conclusions: CD30+ large cells seem to be a common feature in long-standing infiltrates of scabies. CD30 expression in scattered cells of a cutaneous lymphoid infiltrate cannot be assessed as a strong diagnostic argument of neoplastic cutaneous CD30+ lymphoid proliferation (lymphomatoid papulosis/cutaneous CD30+ lymphoma). Therefore, the possibility that large atypical CD30+ cells may be also present in several benign inflammatory diseases should be always considered.

NORWEGIAN Hyperplastic epidermis with acanthosis, papillomatosis, and hyperkeratosis with numerous Scabies mites scattered throughout

SCABIETIC NODULE Children may present with nodular collections of fibrosis with eosinophils and mixed inflammatory cells as a scabid reaction

TREATMENT CHARACTERIZATION

Topical permethrin cream was slightly superior to oral ivermectin in the treatment of scabies J Am Acad Dermatol 2000;42:236-40

Ivermectin
N Engl J Med 1996;333:26-30.
James W, editor. Advances in dermatology. Vol 15. St Louis: Mosby; 1999. p. 67-108

Initially one dose of ivermectin at 200 �g/kg was curative but currently there is uncertainty whether optimal therapy for scabies is 200 to 250 �g/kg given on day 1 and day 8 or whether it is simply a one-dose treatment at 400 �g/kg

Fitzpatrick's Dermatology in General Medicine. 5th Edition. McGraw-Hill. 1999.

Commonly Used Terms

Microbiology and Infectious Disease

Skin

Internet Links

Last Updated 8/16/2002

GROSS APPEARANCE/CLINICAL VARIANTS	CHARACTERIZATION
General
VARIANTS
Norwegian scabies	Cutis 1995;11:18-19 Fulminant and highly infectious form of the disease caused by an immunocompromised state May be present in AIDS patients Thickened plaques with hyperkeratosis mainly affecting acral surfaces, usually not pruritic

HISTOLOGICAL TYPES	CHARACTERIZATION
General	Superficial and deep mixed inflammatory cell infiltrate with lymphocytes, eosinophils, plasma cells, and histiocytes Epidermis may show eosinophilic spongiosis with hyperplasia or parakeratosis The female mite, feces (scybula), egg, and larvae may be present in the stratum corneum
VARIANTS
CD30 POSITIVE CELLS
CD30 antigen expression in cutaneous inflammatory infiltrates of scabies: a dynamic immunophenotypic pattern that should be distinguished from lymphomatoid papulosis. Gallardo F, Toll A, Pujol RM; Carlos Barranco. Department of Dermatology, Hospital del Mar, IMAS, Barcelona, Spain Department of Dermatology, Pathology, Hospital del Mar, IMAS, Barcelona, Spain.	J Cutan Pathol 2002 Jul;29(6):368-73 Abstract quote Background: Expression of CD30 antigen is a distinct marker of lymphocyte activation that was originally described in the Reed-Sternberg cells of Hodgkin's disease. The observation of CD30+ cells has been considered a diagnostic feature of cutaneous CD30 lymphoid proliferations. However, CD30 expression has also been reported in some cutaneous benign inflammatory infiltrates. Methods: Eleven skin biopsies from patients with scabies were double-blindly and retrospectively analysed. A panel of histopathological parameters and immunophenotypic expression of CD4, CD8, CD30 and S-100 antigens was studied. CD30 and S-100 antigens expression were related to clinical features. Results: Large CD30+ cells were demonstrated in eight (8/11) biopsies, corresponding to patients with long-standing lesions (3 months or longer). However, no expression of the CD30 antigen was observed in all biopsy specimens (3/11) corresponding to early lesions (2 months or less). The presence of S-100 positive cells in the papillary dermis was an almost constant feature. Conclusions: CD30+ large cells seem to be a common feature in long-standing infiltrates of scabies. CD30 expression in scattered cells of a cutaneous lymphoid infiltrate cannot be assessed as a strong diagnostic argument of neoplastic cutaneous CD30+ lymphoid proliferation (lymphomatoid papulosis/cutaneous CD30+ lymphoma). Therefore, the possibility that large atypical CD30+ cells may be also present in several benign inflammatory diseases should be always considered.
NORWEGIAN	Hyperplastic epidermis with acanthosis, papillomatosis, and hyperkeratosis with numerous Scabies mites scattered throughout
SCABIETIC NODULE	Children may present with nodular collections of fibrosis with eosinophils and mixed inflammatory cells as a scabid reaction