Global InformationScabies information
| Scabies | |
|---|---|
| Other names | Seven-year itch[1] |
 | |
| Magnified view of a burrowing trail of the scabies mite. The scaly patch on the left was caused by scratching and marks the mite's entry point into the skin. The mite has burrowed to the top-right, where it can be seen as a dark spot at the end. | |
| Specialty | Infectious disease, dermatology |
| Symptoms | itchiness, pimple-like rash[2] |
| Usual onset | 2–6 weeks (first infection), ~1 day (subsequent infections)[2] |
| Causes | Sarcoptes scabiei mite spread by close contact[3] |
| Risk factors | Crowded living conditions (child care facilities, group homes, prisons), lack of access to water, wearing second hand clothing[3][4][5] |
| Diagnostic method | Based on symptoms[6] |
| Differential diagnosis | seborrheic dermatitis, dermatitis herpetiformis, pediculosis, atopic dermatitis[7] |
| Medication | permethrin, crotamiton, lindane, ivermectin[8] |
| Frequency | 204 million / 2.8% (2015)[9] |
Scabies (/ˈskeɪbiːz, ˈskeɪbiiːz/;[10] also sometimes known as the seven-year itch)[1] is a contagious human skin infestation by the tiny (0.2–0.45 mm) mite Sarcoptes scabiei,[1][3] variety hominis. The word is from Latin: scabere, lit. 'to scratch'.[11] The most common symptoms are severe itchiness and a pimple-like rash.[2] Occasionally, tiny burrows may appear on the skin.[2] In a first-ever infection, the infected person usually develops symptoms within two to six weeks.[2] During a second infection, symptoms may begin within 24 hours.[2] These symptoms can be present across most of the body or just certain areas such as the wrists, between fingers, or along the waistline.[2] The head may be affected, but this is typically only in young children.[2] The itch is often worse at night.[2] Scratching may cause skin breakdown and an additional bacterial infection in the skin.[2]
Scabies is caused by infection with the female mite Sarcoptes scabiei var. hominis, an ectoparasite.[3] The mites burrow into the skin to live and deposit eggs.[3] The symptoms of scabies are due to an allergic reaction to the mites.[2] Often, only between 10 and 15 mites are involved in an infection.[2] Scabies is most often spread during a relatively long period of direct skin contact with an infected person (at least 10 minutes) such as that which may occur during sexual activity or living together.[3][12] Spread of the disease may occur even if the person has not developed symptoms yet.[13] Crowded living conditions, such as those found in child-care facilities, group homes, and prisons, increase the risk of spread.[3] Areas with a lack of access to water also have higher rates of disease.[4] Crusted scabies is a more severe form of the disease, not essentially different but an infestation by very large numbers of mites[3] that typically only affects those with a poor immune system; the number of mites also makes them much more contagious.[3] In these cases, spread of infection may occur during brief contact or by contaminated objects.[3] The mite is very small and at the limit of detection with the human eye. It is not readily obvious; factors that aid in detection are good lighting, magnification, and knowing what to look for. Diagnosis is based either on detecting the mite (confirmed scabies), detecting typical lesions in a typical distribution with typical historical features (clinical scabies), or detecting atypical lesions or atypical distribution of lesions with only some historical features present (suspected scabies).[14]
Several medications are available to treat those infected, including oral and topical ivermectin, and permethrin, crotamiton, and lindane creams.[8] Sexual contacts within the last month and people who live in the same house should also be treated at the same time.[13] Bedding and clothing used in the last three days should be washed in hot water and dried in a hot dryer.[13] As the mite does not live for more than three days away from human skin, more washing is not needed.[13] Symptoms may continue for two to four weeks following treatment.[13] If after this time symptoms continue, retreatment may be needed.[13]
Scabies is one of the three most common skin disorders in children, along with ringworm and bacterial skin infections.[15] As of 2015, it affects about 204 million people (2.8% of the world population).[9] It is equally common in both sexes.[16] The young and the old are more commonly affected.[6] It also occurs more commonly in the developing world and tropical climates.[6]
Other animals do not spread human scabies;[3] similar infection in other animals is known as sarcoptic mange, and is typically caused by slightly different but related mites.[17]
- ^ a b c Gates RH (2003). Infectious disease secrets (2nd ed.). Philadelphia: Elsevier, Hanley Belfus. p. 355. ISBN 978-1-56053-543-0.
- ^ a b c d e f g h i j k l "Parasites – Scabies Disease". Center for Disease Control and Prevention. 2 November 2010. Archived from the original on 2 May 2015. Retrieved 18 May 2015.
- ^ a b c d e f g h i j k "Parasites - Scabies: Epidemiology & Risk Factors". Centers for Disease Control and Prevention. 2 November 2010. Archived from the original on 29 April 2015. Retrieved 1 January 2024.
- ^ a b "WHO -Water-related Disease". World Health Organization. Archived from the original on 22 October 2010. Retrieved 10 October 2010.
- ^ Muthiani YM (21 June 2017). "Potential skin pathogens on second hand clothes and the effectiveness of disinfection methods". JKUAT Annual Scientific Conference.
- ^ a b c "Scabies". World Health Organization. Archived from the original on 18 May 2015. Retrieved 18 May 2015.
- ^ Ferri FF (2010). "Chapter S". Ferri's differential diagnosis: a practical guide to the differential diagnosis of symptoms, signs, and clinical disorders (2nd ed.). Philadelphia, PA: Elsevier/Mosby. ISBN 978-0-323-07699-9.
- ^ a b "Parasites – Scabies Medications". Center for Disease Control and Prevention. 2 October 2019. Archived from the original on 30 April 2015.
- ^ a b Vos T, Allen C, Arora M, Barber RM, Bhutta ZA, Brown A, et al. (GBD 2015 Disease and Injury Incidence and Prevalence Collaborators) (October 2016). "Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015". Lancet. 388 (10053): 1545–1602. doi:10.1016/S0140-6736(16)31678-6. PMC 5055577. PMID 27733282.
- ^ Wells JC (2008). Longman Pronunciation Dictionary (3rd ed.). Longman. ISBN 978-1-4058-8118-0.
- ^ Mosby's Medical, Nursing & Allied Health Dictionary (4 ed.). Mosby-Year Book Inc. 1994. p. 1395. ISBN 978-0-8016-7225-5.
- ^ Dressler C, Rosumeck S, Sunderkötter C, Werner RN, Nast A (November 2016). "The Treatment of Scabies". Deutsches Arzteblatt International. 113 (45): 757–762. doi:10.3238/arztebl.2016.0757. PMC 5165060. PMID 27974144.
- ^ a b c d e f "Parasites - Scabies Treatment". Center for Disease Control and Prevention. 2 November 2010. Archived from the original on 28 April 2015. Retrieved 18 May 2015.
- ^ Engelman D, Yoshizumi J, Hay RJ, Osti M, Micali G, Norton S, et al. (November 2020). "The 2020 International Alliance for the Control of Scabies Consensus Criteria for the Diagnosis of Scabies". The British Journal of Dermatology. 183 (5): 808–820. doi:10.1111/bjd.18943. PMC 7687112. PMID 32034956.
- ^ Andrews RM, McCarthy J, Carapetis JR, Currie BJ (December 2009). "Skin disorders, including pyoderma, scabies, and tinea infections". Pediatric Clinics of North America. 56 (6): 1421–1440. doi:10.1016/j.pcl.2009.09.002. PMID 19962029.
- ^ Vos T, Flaxman AD, Naghavi M, Lozano R, Michaud C, Ezzati M, et al. (December 2012). "Years lived with disability (YLDs) for 1160 sequelae of 289 diseases and injuries 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010". Lancet. 380 (9859): 2163–2196. doi:10.1016/S0140-6736(12)61729-2. PMC 6350784. PMID 23245607.
- ^ Georgis' Parasitology for Veterinarians (10 ed.). Elsevier Health Sciences. 2014. p. 68. ISBN 978-1-4557-3988-2.