Scabies: Difference between revisions

 
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==Background==
==Background==
*Infestation with the Sarcoptes scabiei mite
{{Skin anatomy background images}}
*4-6wk incubation period after initial exposure
*Infestation with the ''Sarcoptes scabiei'' mite
**Those previously infected, sx begin in 1-3 days (sensitization)
*4-6 week incubation period after initial exposure
**Those previously infected, symptoms begin in 1-3 days (sensitization)
**Type IV hypersensitivity
*Not a reflection of poor hygiene
*Not a reflection of poor hygiene


==Diagnosis==
==Clinical Features==
*Older children / adults
[[File:PMC3346911 ad-24-194-g002.png|thumb|Traditional infantile scabies.]]
**Generalized eruption w/ linear burrows, papules, pustules
[[File:PMC3346911 ad-24-194-g001.png|thumb|10-X magnification showing numerous scabies heads (arrows).]]
**Hand, feet, groin predominance
[[File:ScabiesD08.JPG|thumb|Scabies]]
*Infants
[[File:Scabies-burrow.jpg|thumb|Scabies burrow at high resolution]]
**Hyperpigmented nodules may be found in axilla and diaper areas
[[File:Norwegian_scabies.png|thumb|Diffuse, hyperkeratotic, yellowish papules seen in Norwegian Scabies]]
**May be generalized
''Seek history of symptomatic close contacts (human or animal)''


==DDx==
===Infants===
*Impetigo
*Hyperpigmented [[pediatric rashes|nodules]], vesiculopustules, papules may be found in axilla and diaper areas
*Atopic dermatitis
*May be generalized
*Insect bites
*Drug reaction
*[[Dermititis Herpetiformis]]


==Treatment==
===Older children / adults===
*Permethrin cream for all family members
*Generalized eruption with linear burrows, papules, pustules
**Apply from neck down
*Predominance in web spaces of the fingers, flexor aspect of the wrists, axillae, groin, nipples, and the periumbilical region
**Infants may require applicatio nto scalp/face (avoid mucus membranes)
*[[Pruritus]] is classically worse at night
**Leave on for 8-12hr before washing off
 
*Ivermectin 200mcg/kg may be necessary for severe infection
===Norwegian Scabies===
*Wash linens/clothes in hot water
*In immunocompromised
*Severe disease with diffuse scabies
*Requires multiple treatments
 
==Differential Diagnosis==
*[[Envenomations, bites and stings|Insect bites]]
*[[Impetigo]]
*[[Atopic dermatitis]]
*[[Drug rash]]
*[[Dermatitis herpetiformis]]
 
{{Ectoparasite DDX}}
{{Travel Skin Conditions DDX}}
{{Maculopapular rash DDX}}
 
==Evaluation==
*Clinical diagnosis, based on history and physical exam
 
==Management==
===General Care===
*Wash all linens/clothes in hot water or bag bulky items and keep sealed for 2wks
*Pruritus may continue for weeks despite successful elimination of infestation
*Pruritus may continue for weeks despite successful elimination of infestation
**Consider steroids for symptom relief
{{Scabies treatment}}
===Avoid===
*'''[[Lindane]]''' - effective treatment but associated with potential for toxic manifestations (seizures, neurotoxicity)
**Reserved for refractory cases
==Disposition==
*Discharge
==See Also==
*[[General approach to rashes]]
==External Links==
*[https://pubmed.ncbi.nlm.nih.gov/16731272/ Heukelbach J, Feldmeier H. Scabies. Lancet. 2006 May 27;367(9524):1767-74. doi: 10.1016/S0140-6736(06)68772-2. PMID: 16731272. Accessed 13 Jan 2021]


==Source==
==References==
Tintinalli
<references/>


[[Category:Derm]]
[[Category:Dermatology]]
[[Category:Peds]]
[[Category:Pediatrics]]
[[Category:ID]]

Latest revision as of 18:13, 11 December 2024

Background

Normal dermal anatomy.
  • Infestation with the Sarcoptes scabiei mite
  • 4-6 week incubation period after initial exposure
    • Those previously infected, symptoms begin in 1-3 days (sensitization)
    • Type IV hypersensitivity
  • Not a reflection of poor hygiene

Clinical Features

Traditional infantile scabies.
10-X magnification showing numerous scabies heads (arrows).
Scabies
Scabies burrow at high resolution
Diffuse, hyperkeratotic, yellowish papules seen in Norwegian Scabies

Seek history of symptomatic close contacts (human or animal)

Infants

  • Hyperpigmented nodules, vesiculopustules, papules may be found in axilla and diaper areas
  • May be generalized

Older children / adults

  • Generalized eruption with linear burrows, papules, pustules
  • Predominance in web spaces of the fingers, flexor aspect of the wrists, axillae, groin, nipples, and the periumbilical region
  • Pruritus is classically worse at night

Norwegian Scabies

  • In immunocompromised
  • Severe disease with diffuse scabies
  • Requires multiple treatments

Differential Diagnosis

Domestic U.S. Ectoparasites

See also travel-related skin conditions

Travel-related skin conditions

See also domestic U.S. ectoparasites

Maculopapular rashes

Evaluation

  • Clinical diagnosis, based on history and physical exam

Management

General Care

  • Wash all linens/clothes in hot water or bag bulky items and keep sealed for 2wks
  • Pruritus may continue for weeks despite successful elimination of infestation
    • Consider steroids for symptom relief

Adults

  • Permethrin 5% cream for all family members[1]
    • Apply from neck down
    • Leave on for 8-12hr before washing off
    • Has 95-98% success rate, may reapply in 1-2wks if incomplete effect
  • Ivermectin 200 mcg/kg may be necessary for severe infection
    • Also viable option in adolescent or adult with insecure social situation
    • Success rate 70%, increases if give repeat dose 2wks after
    • Contraindicated in lactating women and children < 15kg

Infants

  • Permethrin 5% is FDA approved for > 2 months of age although still recommended for neonatal scabies[2]
    • May require application head to toe (avoid mucus membranes)
    • Leave on for 8-12 hours, then wash off

Avoid

  • Lindane - effective treatment but associated with potential for toxic manifestations (seizures, neurotoxicity)
    • Reserved for refractory cases

Disposition

  • Discharge

See Also

External Links

References

  1. Strong M. Johnstone P. Interventions for treating scabies. Cochrane Database Syst Rev. 2007;(3):CD000320
  2. Subramaniam S. Rutman MS. Wnger JK. A papulopustular, vesicular, crusted rash in a 4-week old neonate. Pediatric Emergency Care. 2013;29:1210-1212