Penis & scrotum
Infectious
Scabies
Authors: Alcides Chaux, M.D., Antonio L. Cubilla, M.D.
Topic Completed: 1 February 2010
Minor changes: 27 October 2020
Copyright: 2002-2021, PathologyOutlines.com, Inc.
PubMed Search: Scabies penis
Table of Contents
Definition / general | Sites | Etiology | Clinical features | Case reports | Treatment | Clinical images | Microscopic (histologic) description | Microscopic (histologic) imagesCite this page: Chaux A, Cubilla AL. Scabies. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/penscrotumscabies.html. Accessed January 23rd, 2021.
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
- 45 year old man with HIV and localized crusted scabies on glans (Sex Transm Infect 2004;80:72)
- 52 year old woman with lesions on leg (Case of the Week #160)
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
Contributed by Daniel Ostler, D.O. (Case #160)
Lesion on leg (fig 1 and 2: mites in the epidermis; fig 3: mite and scybala, hardened masses of feces)
Images hosted on other servers:
Mite
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
