Penis and scrotum
Infectious disorders
Scabies

Authors: Antonio Cubilla, M.D., Alcides Chaux, M.D. (see Authors page)

Revised: 30 March 2018, last major update February 2010

Copyright: (c) 2002-2018, PathologyOutlines.com, Inc.

PubMed Search: Scabies penis

Cite this page: Cubilla, A., Chaux, A. Scabies. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/penscrotumscabies.html. Accessed September 22nd, 2018.
Definition / general
  • Most common parasitic infection of penis, usually part of generalized infection
Sites
  • Red papules or nodules on glans, shaft and scrotum are typical
Etiology
  • Caused by infestation with mite Sarcoptes scabiei var. hominis, which burrows into the skin and causes intense itching
  • Spread by prolonged (15 - 20 minutes) skin to skin contact with an infected individual, often as a sexually transmitted disease or between members of a household
  • Animals can get scabies but do not spread human scabies
Clinical features
  • First human disease recognized as caused by a specific pathogen (eMedicine: Scabies [Accessed 30 March 2018])
  • Highly contagious and difficult to diagnose early
  • Symptoms may not occur for up to 6 weeks after infection (Clin Microbiol Rev 2007;20:268)
  • Diagnosis requires examining the skin for burrows, then confirming the presence of mites, ova or scybala by microscopy (Dermatol Ther 2009;22:279)
  • Main symptom is intense pruritus, which is worse at night or after hot baths
  • Small crooked lines 4 - 6 mm long (scabetic burrows) and erythematous papules and nodules are often present on glans, shaft and scrotum
  • Excessive scratching may lead to sores, bacterial infections and even glomerulonephritis (Postgrad Med J 2004;80:382)
  • Patients with immunocompromise are at risk for developing "crusted scabies," also called "Norwegian scabies," characterized by scaly rashes, a thickening of the skin and an overwhelming number of mites (J Am Podiatr Med Assoc 2004;94:583)
  • Clinically, scabies can mimic eczema, mycosis fungoides, syphilis and bullous pemphigoid (Dermatol Online J 2006;12:19)
  • Scratch marks often obscure signs of burrows
Case reports
Treatment
  • Topical permethrin (drug of choice), crotamiton (CDC: Scabies [Accessed 30 March 2018]); possibly topical lindane or oral ivermectin (Am J Clin Dermatol 2002;3:9)
  • Topical treatments must coat the body to be effective
  • Household members and close personal contacts should be treated at the same time
  • Nodules may persist for weeks after mites are killed
  • Bedding or clothing of infected individuals should be machine washed and dried with hot water or sealed in a plastic bag for at least 3 days (CDC: Scabies [Accessed 30 March 2018])
Clinical images

Images hosted on other servers:

Mite

Burrow



Penile lesions:

Various images

Various images



Arm / hands:

Norwegian scabies in AIDS patient

Multiple vesicles and tense bullae

Small erythematous papules

With secondary infection

With leprosy

Hand


Palm

Arm of infant



Legs / feet:

Crusted scabies

Depigmentation

Leg



Other sites:

Eyelid

Buttocks

Erythematous vesicles and papules are present on torso extremities, some with adjacent linear excoriations

Crusted scabies

Microscopic (histologic) description
  • Mite and scybala (hardened masses of feces) in epidermis
  • Scabetic burrows are observed in the stratum corneum of the epithelium
Microscopic (histologic) images

Images hosted on other servers:

Mite

Lesion on leg (fig 1 and 2: mites in the epidermis; fig 3: mite and scybala, hardened masses of feces)

Crusted scabies: show
multiple mites (arrows)
in hyperkeratotic
stratum corneum


Intact bulla on forearm

Neutrophils, eosinophils and fibrin

Hyperkeratosis, inflammatory response

Serial section of mite

Scabies

Routine scabies:
single mite;
eosinophilic spongiosis
may be present