HistoryThis section has been translated automatically.
DefinitionThis section has been translated automatically.
Frequent, globally spread, highly itchy parasitic skin infection caused by Sarcoptes scabiei hominis. The reactive dermatitis induced by the infection is to be interpreted as an immunological reaction of the organism to the mite components. The skin symptoms vary considerably depending on the age of the disease, individual reaction situation and intensity of body care.
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PathogenThis section has been translated automatically.
Acarus siro var. hominis o. Sarcoptes scabiei hominis. See below Mites. Female scabies mites grow to 0.3-0.5 mm (males 0.21-0.29 mm) and are just visible as a black dot. Mating occurs on the surface of the skin. Male mites then die. Female mites dig tunnel-shaped tunnels in the stratum corneum and remain viable for about 30-60 days. Oxygen uptake by the mite occurs by diffusion over the skin surface. As a result, the mites penetrate only into the stratum corneum, rarely deeper. They lay 2-3 eggs per day, from which larvae hatch after 2-3 days. Scabies mites cannot survive outside the body for more than 48 hours. In immunocompetent patients, the number of mites found is low (10-12/patient). In immunocompetent patients, the number can increase to > 1 million mites (picture of scabies norvegica).
Occurrence/EpidemiologyThis section has been translated automatically.
Frequent, 200-400 million diseases/year worldwide. The prevalence is mainly based on socio-economic conditions, population density and hygienic circumstances. It fluctuates between < 1% and 30-40% and occurs epidemically.
EtiopathogenesisThis section has been translated automatically.
The transmission of the mated female by close physical contact (sexual contact, warmth of bed, living together in a small space, between children), less often via linen, textiles or fleeting contact (exception: Scabies norvegica). The risk of getting infected through bed linen in which a scabies patient had been lying is < 1: 200.
According to the classification of Coombs and Gell, post-scabial eczema is an allergic reaction of type IV (late type allergic reaction). The female scabies mite lays 4-6 eggs a day in so-called mite ducts, which are located in the stratum corneum and can reach the stratum granulosum. The mite eggs are recognized by the body as antigens and are internalized by Langerhans cells to be presented as T-helper cells which then release pro-inflammatory cytokines and chemokines to eliminate the target cells.
Efflorescence(s)This section has been translated automatically.
LocalizationThis section has been translated automatically.
Especially interdigital wrinkles of hands and feet, elbows, anterior axillary fold, areola, navel, girdle region, penis, ankle region, contact surfaces of the glutaeen. The back is less frequently affected, head and neck as well as palmae and plantae are always free, (exception in old people with atrophic palmae and plantae; in neglected patients the palms of the hands and soles of the feet may also be affected).
With long-term (unkempt) scabies, the emphasis on the typical "scabies regions" is lost. A generalised eczema picture then appears (picture of microbial eczema).
In infants and toddlers: basically ubiquitous, also Palmae and Plantae affected; back of fingers and feet, face.
Clinical featuresThis section has been translated automatically.
Clinically symptomatic is a scabies in the first disease only 3-6 weeks after infection. In case of reinfection the clinical symptoms develop after 24 hours. This means that the mite is literally scratched out of the skin.
The leading symptom of the scabies is a strong itching, especially at night. In addition, there are tortuous, millimetre-long, clearly palpable mite ducts with the mite recognisable as a dark dot at the end of the duct (mite mound). Scratching effects, eczematisation and secondary bacterial infections usually characterise the clinical picture.
Other special forms:
- Cultivated scabies: Clinically only isolated papules; diagnostically important is the detection of mite ducts, which must be searched for. The strong nocturnal itching is a signpost.
- Neglected scabies: Clinical picture of an extensive "microbial eczema". Gang structures must be searched for, they are not in the foreground of the clinical picture. It is not uncommon for plaques to form over the entire surface. Also weeping or pustular areas.
- Persistent scabies granuloma: In infants and adults, even after sufficient antiscabial therapy, severely itching, 2-4 mm large, mostly scratched papules may persist, probably as a hyperergic reaction to the persistent scabies allergen (late type reaction).
- Post-scabial itching: Itching persists for several days or even weeks after sufficient scabies treatment.
- Scabies incognita: Glucocorticoids, applied systemically or locally, can completely hide the clinical symptoms.
- Localised scabies: A therapy-resistant nipple eczema may be an example of a localised scabies.
- Scabies in infants and toddlers: The face, head, neck and often (sometimes exclusively) Palmae and Plantae are affected. Efflorescences in children are often very succulent. Excruciating itching persists. Blisters and pustules may occur. These may be clinically formative.
- Scabies in seniors: especially in patients with dementia, the scabies is often clinically atypical, e.g. without the typical pruritus (in a larger study in 61% of cases), only recognizable by treatment-resistant eczematous lesions (Cassell JA et al. 2018).
- Native detection of mites: opening of the mite duct by means of a fine cannula, application of the contents on a microscope slide, native examination under the microscope.
- It is also possible to visualise the mite duct by dabbing a dye (felt pen) and applying an alcohol drop (dye is sucked into the duct by capillary forces).
- Microscopic mite detection by means of reflected-light microscopy (high sensitivity) (brownish triangular contour, formed by the front part of the mite!)
- Histological detection of mites (especially in Scabies norwegica easily possible; otherwise mite detection is only possible in step sections, if at all).
HistologyThis section has been translated automatically.
Differential diagnosisThis section has been translated automatically.
- Histological: Allergic contact dermatitis; atopic eczema; other arthropod reactions.
- Clinical signs: contact dermatitis; atopic eczema; microbial eczema; contagious impetigo; Paget's disease (for nipple eczema), dermatitis herpetiformis, diseases with erythroderma, pseudo-scratches.
Complication(s)This section has been translated automatically.
General therapyThis section has been translated automatically.
External therapyThis section has been translated automatically.
- Adults and adolescents:
- Permethrin 5% in a cream base (e.g. InfectoScab®) is the first choice therapy. Apply once for 8-12 hours, repeat after 14 days if necessary. In case of severe infestation with stationary treatment indication we recommend a 3-day local treatment.
- Alternative: Crotamiton (e.g. CROTAMITEX®) (see below).
- Alternative: Benzyl benzoate (see below), in case of itching at the capillitium, co-treatment of the hairy scalp with Antiscabiosum 25% is possible, as this can be washed out of the hair as an emulsion.
- Alternative: Allethrin I (e.g. Jacutin® MethylprednisolonaceponateMethylprednisolonacepona, Spregal® Spray (+ Piperonylbutoxide).
- Alternative: 0.5% aqueous malathion lotion.
- Alternative: 1% ivermectin lotion .
Remark! Additional daily change of outer clothing and bed linen. Bed linen should be washed at > 60 °C. Alternative: Store in a plastic bag for 3-5 days. The mites will then die.
- Alternative (rarely used): 5% tea tree oil.
- Alternative (rarely used): 10% precipitated sulphur in vaseline or hydrophilic base(sulphur cream 2.5-10%): apply 2 times/day for 3-7 days each time after a soap bath.
- Pregnancy (see below Pregnancy, Prescriptions):
Remark. None of the above-mentioned agents is approved, therefore in pregnant women these therapy modalities are applicable in off-label use! Permethrin is listed in the Red List as a Group 4 drug, i.e. there is insufficient experience of its use in humans; in animal studies there is no evidence of embryotoxic/teratogenic effects.
- Permethrin 5% in a cream base (e.g. InfectoScab) is therapy of first choice. Apply once for 8-12 hours, repeat after 14 days if necessary.
- Benzyl benzoate (e.g. Antiscabiosum Mago 25%; alterative NRF formulation: benzyl benzoate emulsion 10 or 25 %: apply once/day, use for 3 days, then shower off.
- Alternatively: 10% Crotamiton ointment (e.g. Crotamitex® gel/lotion/ointment)apply for 3-5 consecutive days. Cure rates vary between 50-70%.
- Nursing mothers: Therapy as for pregnant women.
- Primarily apply permethrin and benzyl benzoate, see above. (Pyrethroids pass into breast milk; nothing is known about benzyl benzoate). According to the S1 guideline of the German Dermatological Society (as of 2016), a breastfeeding break of 5 days should be observed after treatment with permethrin and benzyl benzoates.
- Newborns and infants:
- Permethrin 2.5% ( R194 ), applied once over 8-12 hours. Treatment of the entire integument including the head (excluding the mouth and eye area).
- Alternative: Apply crotamiton ointment for 3-5 consecutive days.
- Benzyl benzoate is not recommended; it is banned in the USA because of the so-called Gasping syndrome (severe progressive encephalopathy with metabolic acidosis and other symptoms). This syndrome occurred in infants whose catheters and infusion systems were flushed with benzyl alcohol.
- Infants or older children:
- Permethrin: Up to 2 years of age 2.5% ( R194 ), from 2 years of age 5% (e.g. Infectoscab 5.0% cream, not on the capillitium as it cannot be washed out of hair) applied once over 8-12 hrs.
- Alternatively: Benzyl benzoate 10% (e.g. Antiscabiosum Mago 10% for children, if necessary treatment of the capillitium is possible, as the emulsion can be washed out of the hair; or apply benzyl benzoate emulsion 10 or 25 % ( R027 ) once a day, apply for 3 days, then shower off.
Reminder. Use of benzoyl benzoate is prohibited in neonates in the USA (deaths when using infusion systems purified with benzyl alcohol [so-called Gasping syndrome = progressive encephalopathy, metabolic acidosis, bone marrow depression])!
- Alternative: 2,5% precipitated sulphur in vaseline or hydrophilic base ( R232 ): apply 2 times/day for 3-7 days each time after a soap bath (Cave: odour nuisance).
- Immunosuppressed patients:
- Permethrin 5% as recommended for adults. Repeat after 14 days.
- In case of recurrence, in addition to local therapy, peroral application of ivermectin.
- Severely eczematized patients:
- Pretreatment with a glucocorticoid externum (e.g. 1% hydrocortisone cream) for 2-3 days; followed by classical antiscabi therapy.
Internal therapyThis section has been translated automatically.
In case of therapy resistance (frequent in patients with HIV infection), systemic therapy with ivermectin (e.g. Driponin® or Scabioral®) is recommended. Dosage: 200 µg/kg bw p.o. (max. up to 400 μg/kg bw) as a single dose, in cases of doubt always round up to whole 3 mg tablets. There is no maximum limit to the number of tablets to be taken. Calculated number of tablets to be taken all at once (with water) and 2 hours apart with a meal (empty stomach). This is usually a one-time treatment. Treatment may need to be repeated after 2-4 weeks. A return to communal facilities can take place after 24 hours according to the RKI recommendations (see source 1) if ivermectin is taken correctly.
NaturopathyThis section has been translated automatically.
AftercareThis section has been translated automatically.
Pre- and post-treatment: Glucocorticoid-containing topical preparations such as 0.25% prednicarbate (e.g. Dermatop® cream) or methylprednisolone aceponate (Advantan® cream or lotion) are used for post-treatment and in cases of severely oozing, irritated skin prior to therapy. Since killed mites continue to act as allergens in the skin for weeks, itching often persists for some time after treatment. For open, weeping areas, moist compresses with antiseptic additives such as potassium permanganate , see also Eczema, post-scabious.
Notice. Persistent itchy eczema in treated scabies is often due to sensitization to killed mites, but occasionally due to resistance to antiscabiosa or reinfection! Scabies granulomas should be treated with topical glucorticoids (under occlusion if necessary). In some cases, local injections with glucocorticoid crystal suspensions are necessary.
In contact persons: examination, co-treatment if disease is suspected.
Note(s)This section has been translated automatically.
- If left untreated, the scabies is chronic, but can heal spontaneously even after several years.
- Resistance has been described for permethrin, crotamiton, lindane and benzoyl benzoate.
Notice! Studies on the evidence and efficiency of topical antiscabial agents show the best results with permethrin.
- School attendance is possible again after a single application of permethrin!
LiteratureThis section has been translated automatically.
- Agathos M (1994) Skabies. dermatologist 45: 889-903
- American Academy of Pediatrics (Scabies). In: Peter, G. (eds.) 2000 Red Book: Report of the Committee on Infectious Diseases, 25th ed. Elk Grove Village, IL pp. 506-508.
- Aristotle (340 BC) (1960) Animalium historia. In: Aristotle's opera, Volume I. De Gruyter Publishers
- Bezold G et al (2001) Hidden scabies: diagnosis by polymerase chain reaction. Br J Dermatol 144: 614-618
- Cassell JA et al (2018) Scabies outbreaks in ten care homes for elderly people: a prospective study ofclinical
features, epidemiology, and treatment outcomes.Lancet Infect Dis 18:894-902.
- Chosidow O (2000) Scabies and pediculosis. Lancet 355: 819-826
- Chouela E et al (2002) Diagnosis and treatment of scabies: a practical guide. At J Clin Dermatol 3: 9-18
- Dupuy A et al (2006) Accuracy of standard dermoscopy for diagnosing scabies. J Am Acad Dermatol 56: 53-62
- Folster-Holst R et al (2000) Treatment of scabies with special consideration of the approach in infancy, pregnancy and while nursing. dermatologist 51: 7-13
- Haas N (1987) A simple vital-microscopic aid for the detection of the scabies mite. Z Hautkr 62: 1395-1398
- Hu S et al (2008) Treating scabies results. Arch Dermatol 144: 1638-1641
- Karre S et al (1997) Steroid-induced Scabies norvegica. dermatologist 48: 343-346
- Madan V et al (2001) Oral ivermectin in scabies patients: a comparison with 1% topical lindane lotion. J Dermatol 28: 481-484
- Müllegger RR et al (2010) Skin infections during pregnancy. dermatologist 61: 1034-1039
- Paasch U, Haustein UF (2001) Treatment of endemic scabies with allethrin, permethrin and ivermectin. Evaluation of a treatment strategy. dermatologist 52: 31-37
- Tzenow et al (1997) Oral treatment of scabies with ivermectin. Dermatologist 48: 2-4
- Walton S et al (2004) Acaricidal activity of melaleuca aternifolia (tea tree) oil. Arch Dermatol 140: 563-566
Incoming links (53)Acariasis; Acropustulose infantile; Allethrin i; Antiparasitosa; Arthropods; Asteatotic dermatitis; Benzyl benzoate; Benzyl benzoate emulsion 10 or 25 % (nrf 11.64.); Breast dermatitis; Caterpillar dermatitis; ... Show all
Outgoing links (35)Allergen; Allethrin i; Benzyl benzoate; Benzyl benzoate emulsion 10 or 25 % (nrf 11.64.); Breast dermatitis; Collagenosis reactive perforating; Crotamiton; Eczematous scabies; Glucocorticosteroids; Glucorticosteroids topical; ... Show all
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