Treating the infection or eczema sometimes reveals the underlying scabies infection. Treatment involves the use of topical creams or lotions. Permethrin is the most effective and commonly used.
It is considered safe in pregnancy but shouldn't be used on those under two months of age. Malathion and Crotamiton cream are also an option, though considered less effective. These are not recommended in pregnancy. The lotion must be applied covering the whole body from the neck down and left on for 24 hours. Scabies rarely affects the face so treating here is not necessary. If hands are washed after application, the lotion should be reapplied. Bed sheets and underwear should be washed but, as the mite can't live for long away from the body, a deep clean of the whole house is not necessary.
Cleaning mites from under the nails is important. All household contacts must be treated whether they itch or not. Skin will stay itchy for several weeks after. This does not mean infection is ongoing. The lotion kills mites but itch can persist until body parts and mite faeces are shed from the skin in the normal way over several weeks. If eczema has occurred secondary to scratching, taking an antihistamine and using steroid creams may help.
Get the best home, property and gardening stories straight to your inbox every Saturday. Enter email address This field is required Sign Up. Learn More. Scabies is a significant public health condition in long-term care facilities, plaguing even developed countries. Although treatments are available, eradication and control of scabies cases still remain a challenge due to delays in diagnosis and difficulties in maintaining preventive and surveillance measures. Prompt treatment of patients and their contacts that are affected, along with concomitant education of health staff and family members, are paramount.
Environmental disinfestation is also a concern. Scabies is often a neglected parasitic disease. It has long been known to human beings, first described by the renowned physician Jeremy Thriverius of the Habsburgian Low Countries during the 16th century. The causal relationship between skin infestation and the scabies mite was first established by Giovan Cosimo Bonomo, an Italian physician, and the apothecary Diacinto Cestoni [ 1 ].
Scabies is a significant public health condition both in resource-poor and developed countries [ 2 ], affecting individuals of every age and socioeconomic status [ 3 ]. Incidentally, the role of poor hygiene in scabies occurrence has been overestimated and is probably more attributable to overcrowding [ 4 , 5 , 6 ]; this is noted in institutional outbreaks, where high standards of cleanliness are observed [ 7 , 8 ].
Outbreaks in residential and long-term care facilities, however, are usually caused by diagnosis delay and are therefore difficult to control [ 9 ]. A systematic review of population-based studies found the highest prevalence of scabies in Papua New Guinea, Panama, and Fiji [ 10 , 11 ]. Scabies caused 0. Prevalence of institutional scabies is probably underestimated [ 14 ].
In one review of outbreaks in elderly care facilities caused by 37 pathogens, scabies was the fifth most reported pathogen after influenza and noroviruses, Salmonella spp.
This ectoparasite infestation is caused by the mite Sarcoptes scabiei variety hominis. Both male and female mites are invisible to the unaided eye; the maximum adult size is 0. Scabies is transmitted through skin-to-skin contact, though less frequently through fomites inanimate objects capable of transmitting an infectious organism such as clothing, towels, and bed linens [ 17 , 18 , 19 , 20 ]. Among adults, sexual contact is an established mode of transmission [ 3 ]. Mites dislodged from an infested individual use odor and heat to locate a new host [ 4 ].
The probability of being infected is related to the number of mites on the infested individual and the length of contact [ 3 , 17 ]. In colder temperatures and higher humidity, they can survive even longer. To a lesser extent, transmission can happen through fomites [ 18 , 19 , 21 , 22 , 23 ].
Female mites burrow into the epidermis, while male mites explore the skin for an unfertilized female. Female mites live for 4—6 weeks, producing 2—4 ova a day [ 16 , 24 ].
A single female mite can produce up to 40 ova during her lifetime, the larvae hatching days thereafter. Larvae molt into protonymphs 3—4 days and then tritonymphs 2—5 days before turning into adult male or female mites 5—6 days.
In total, mature adults develop within 10 to 14 days [ 2 ]. However, this period is shorter in people who have been previously infested, whereby symptoms typically develop within 1 to 5 days of re-exposure due to rapid sensitization [ 3 , 18 ].
The two major clinical variants of scabies are classic and crusted. Classic scabies, the most common presentation, is associated with a relatively low mite burden approximately 10—15 mites on the body. Crusted scabies usually occurs in older adults, individuals with dementia, immunocompromised individuals, and individuals with severe neurological disease [ 9 , 25 , 26 ]. It is associated with a higher mite burden of up to millions of mites on the body [ 27 ]. Other forms of scabies include bullous scabies that can mimic bullous pemphigoid, scabies incognito, and hidden scabies [ 28 ].
The pathognomonic signs of scabies are burrows, erythematous papules, along with the symptom of pruritus nocturnal predominance [ 2 , 4 ]. Burrows are serpiginous, whitish lines in the upper epidermis, measuring several millimeters in length. Typical areas where signs of infestation can be observed are the interdigital spaces of the hand, flexural aspect of the wrists, elbows, penis shaft, nipples, buttocks, axillae, and periumbilical area.
In infants and the elderly, classic scabies can present atypically on the head, face, back, and diaper area [ 2 , 24 , 29 ]. Crusted or Norwegian scabies affect patients with HIV-infection, human T-cell lymphotropic virus type 1, other immunocompromised patients, and those with sensory and motor neuropathy or dementia [ 29 , 30 , 31 , 32 ].
Sometimes it affects persons without apparent risk factors [ 3 ]. Lesions are described as erythematous, hyperkeratotic, psoriasiform, warty, and exfoliating, scaly rash over the scalp, face, fingers, genitalia, and even nails [ 4 , 29 ]. Inappropriate long-term application of potent topical steroids, especially in the elderly, can lead to crusted scabies [ 29 ]. The reaction can be delayed for up to four weeks, which accounts for long latency of the disease [ 33 ].
Both cell-mediated host immune response and humoral response play roles in the host immune response [ 2 , 18 ]. Increased serum levels of IgG and IgE combined with peripheral eosinophilia are not protective against reinfestation [ 2 ]. Scabies mites are not known to transmit secondary infections. However, severe scratching can lead to secondary skin infection. Secondary skin infections are not limited to boils, cellulitis, pyoderma, or lymphangitis due to Streptococcal pyogenes.
Streptococci and staphylococci have been isolated from skin burrows as well as mite fecal pellets, suggesting that the mites themselves may contribute to the spread of pathogenic bacteria [ 5 ]. Bacterial superinfections, however, are uncommon in immunocompetent adults living in Western countries [ 34 ]. Secondary infection of scabies with S. Diagnosis is based on the contact history of the patients, health care workers, or even family members.
The combination of pruritic eruptions, characteristic lesions and their distribution, and the identification of mites, eggs, or feces on skin scrapings confirm the diagnosis.
In practice, burrows are often obliterated by bathing, scratching, formation of crusts, or superinfection [ 4 ]. Visibility of burrows can be improved with an ink burrow test, where burrows will absorb the ink and be readily apparent as ink-filled wavy lines where the mite has tunneled, called the stratum corneum [ 36 ].
The usual method of obtaining skin samples is accomplished through skin scraping. In this method, the scalpel should ideally be oil-covered as the oil helps to keep the scraped content adhering to the blade [ 2 ]. Multiple superficial skin samples should be obtained from characteristic lesions by scraping laterally across the skin cautiously to avoid bleeding [ 24 ].
Scrapings are then placed on a covered slide for direct microscopic examination. Video dermatoscopy is suitable for clinching diagnosis in children. With a magnification of up to times, mites and burrows can be identified [ 37 ]. Performed by a trained practitioner, dermatoscopy yields high accuracy in diagnosing scabies [ 38 , 39 ]. Epiluminescence microscopy using dermatoscopy has also been used in dermatology clinics to identify in vivo mites with good sensitivity [ 40 ]. Serology tests have yet to be successful in human infestations [ 43 ].
Complementary DNA libraries have been constructed for S scabiei var. Identification and early treatment of suspected scabies is critical especially in residential or care facilities. Delays in diagnosis have been reported in nursing homes where it was misdiagnosed as eczema and other skin conditions by visiting general practitioners GPs until that diagnosis was superseded by another GP [ 25 ].
Most nursing homes and institutional residential or care facilities do not have access to specialist dermatological support [ 25 ]. The list of differential diagnoses is extensive and includes atopic dermatitis, contact dermatitis, folliculitis, impetigo, papular urticarial, bites from midges, fleas, lice, bedbugs, and other mites , and tinea [ 2 , 3 ]. Nearly all pruritic dermatoses have to be considered differential diagnoses [ 4 ].
The principle of treatment of scabies is rapid isolation and treatment of the index case, identifying contacts, and environmental disinfestations [ 47 ]. It is imperative for the close contacts of individuals diagnosed with scabies to be treated simultaneously because they may have been infected without yet manifesting the symptoms, and so act as reservoirs for infection [ 48 , 49 , 50 , 51 ].
Isolation and locking of doors for residents with dementia and wandering behavior is essential, although it can be distressing to them and staff [ 25 ].
Most scabies infestations are treatable with scabicides. It is essential that steps for environmental disinfection take place simultaneously with medical treatment. Topical treatments typically require application from the neck down to the soles of the feet including fingernails and toenails for duration of many hours. There is no international consensus on the appropriate schedule of treatment, and recommendations in one jurisdiction may not be applicable in others [ 14 , 48 , 52 ].
In a review of interventions for scabies, permethrin was found to be more effective than other scabicides [ 53 ]. A recent review found no difference detected in the efficacy of permethrin in comparison to ivermectin [ 54 ]. Although malathion has been used with success in many centers, there are no trials to compare the effectiveness of malathion against other scabicides [ 53 ]. Table 2 summarizes commonly used treatments for scabies. Efficacy of one application in comparison to two applications has not been formally tested [ 16 ].
Application of topical therapy above the neck level should be considered in children and the elderly who have significant scalp involvement. Antihistamines and emollients are useful for symptomatic management of itch, including medication-related post-scabetic itch [ 49 ].
Topical keratolytics such as salicylic acid can be used to treat crusted scabies. It is applied on days where scabicide is not applied.
Of late, the resistance to scabicides has been increasingly reported [ 55 , 56 , 57 , 58 , 59 ]. Four different players that could potentially contribute to scabicide resistance have been identified as follows: a voltage-gated sodium channels, b glutathione S-transferase GST , c ATP-binding cassette transporters, and d ligand-gated chloride channels [ 57 ].
Moxidectin an established treatment of scabies in dogs and sheep is currently being evaluated as an oral agent for scabies. It is related to ivermectin and has the same mechanism of action, but is more lipophilic retains in tissue longer.
The prospect of moxidectin as future therapy for scabies has been promising [ 60 , 61 , 62 ]. However, the animal mite cannot reproduce on a person and will die on its own in a couple of days. Scabies is spread by prolonged skin-to-skin contact with a person who has scabies. Scabies sometimes also can be spread by contact with items such as clothing, bedding, or towels that have been used by a person with scabies, but such spread is very uncommon unless the infested person has crusted scabies.
Scabies is very unlikely to be spread by water in a swimming pool. Except for a person with crusted scabies, only about scabies mites are present on an infested person; it is extremely unlikely that any would emerge from under wet skin.
Although uncommon, scabies can be spread by sharing a towel or item of clothing that has been used by a person with scabies. Scabies mites do not survive more than days away from human skin.
Items such as bedding, clothing, and towels used by a person with scabies can be decontaminated by machine-washing in hot water and drying using the hot cycle or by dry-cleaning. Items that cannot be washed or dry-cleaned can be decontaminated by removing from any body contact for at least 72 hours.
Because persons with crusted scabies are considered very infectious, careful vacuuming of furniture and carpets in rooms used by these persons is recommended. Back To Top. The rash and itching of scabies can persist for several weeks to a month after treatment, even if the treatment was successful and all the mites and eggs have been killed.
Your health care provider may prescribe additional medication to relieve itching if it is severe. Symptoms that persist for longer than 2 weeks after treatment can be due to a number of reasons, including:.
If itching continues more than weeks or if new burrows or rash continue to appear, seek the advice of a physician; retreatment with the same or a different scabicide may be necessary. The doctor can examine the person, confirm the diagnosis of scabies, and prescribe an appropriate treatment.
Sleeping with or having sex with any scabies infested person presents a high risk for transmission. The longer a person has skin-to-skin exposure, the greater is the likelihood for transmission to occur. Although briefly shaking hands with a person who has non-crusted scabies could be considered as presenting a relatively low risk, holding the hand of a person with scabies for minutes could be considered to present a relatively high risk of transmission. However, transmission can occur even after brief skin-to-skin contact, such as a handshake, with a person who has crusted scabies.
In general, a person who has skin-to-skin contact with a person who has crusted scabies would be considered a good candidate for treatment. To determine when prophylactic treatment should be given to reduce the risk of transmission, early consultation should be sought with a health care provider who understands:. Contact Us. Skip directly to site content Skip directly to page options Skip directly to A-Z link. Parasites - Scabies. Section Navigation.
Facebook Twitter LinkedIn Syndicate. Minus Related Pages. Apply it in a thin layer on your skin and leave it on for 8 to 14 hours.
After 8 to 14 hours, wash it off by taking a shower or bath. Because the itching is caused by a reaction to the mites and their waste, it may continue for several weeks after treatment, even if all the mites and eggs are killed.
You may need to repeat the treatment or take an oral medication instead. You can buy an antihistamine at your local pharmacy without a prescription. Read the instructions that come with the medication to find out the correct dose. If a child has scabies, check with their healthcare provider to find out the correct dose. If needed, your healthcare provider may also prescribe an anti-itch cream. The people who have close contact with you, such as family members, roommates, or sexual partners, need to be treated for scabies at the same time that you are.
Scabies is almost always spread by close skin-to-skin contact with a person who has scabies. Scabies is spread most easily between sexual partners and people who live together. A scabies mite can live on a person for 1 to 2 months and can spread to another person at any point during that time. Scabies can also be spread indirectly by sharing things such as clothing, towels, or bedding with a person who has scabies, but this is rare. Indirect spread of scabies usually only happens with crusted scabies.
Without a person to live on, a scabies mite can survive for 2 to 3 days.
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