ScabiesMANAGEMENT

INFECTIOUS DISEASE PRESENTATIONS · 12 SECTIONS

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341 items

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01Approach to the Critical Patient/attcp45

Triage and Infection Control

›Immediate safety priorities

›Airway compromise signs

›Stridor

›Facial or oropharyngeal swelling

›Severe systemic illness concern

›Fever with hypotension

›Altered mental status

›High transmissibility setting

›Shelter

›Long term care

›Contact precautions triggers

›Suspected scabies with diffuse pruritus and close contact spread

›Gown and gloves for direct contact

›Dedicated equipment when feasible

›Crusted scabies concern

›Gown and gloves for all room entry

›Consider hair cover and shoe covers for heavy scale

›Outbreak signals

›Multiple linked cases within household or facility

›Public health notification per local protocol

›Unit wide contact tracing

Red Flags and Escalation

›High risk presentations

›Crusted scabies phenotype

›Hyperkeratotic crusting

›Minimal pruritus despite heavy burden

›Secondary bacterial infection

›Spreading erythema

›Purulence

›Immunocompromised host

›Hematologic malignancy

›Chronic systemic corticosteroids

›If sepsis physiology, then ED resuscitation pathway

›Lactate and blood cultures before antibiotics when feasible

›Broad spectrum antibiotics per local skin and soft tissue protocol

›Source control planning for abscess

Key Concepts

›Scabies working model

›Ectoparasitic infestation by Sarcoptes scabiei var hominis

›Hypersensitivity mediated pruritus

›Burrows and papules from mite activity

›Transmission

›Prolonged skin to skin contact

›Fomite risk higher with crusted scabies

›Coding alignment

›ICD-10 B86 scabies

›SNOMED CT scabies disorder concept

02History/hx32

Symptom Pattern

›Symptom timeline

›Pruritus onset and duration

›Nocturnal predominance

›Recent worsening after partial treatment

›Rash pattern

›Papules and excoriations

›Burrow description by patient

›Pruritus modifiers

›Worse with warmth

›Partial relief with antihistamines

Exposure and Transmission

›Close contact risk

›Household members with itch

›Sexual contact exposure

›Childcare or school exposure

›Institutional risk

›Long term care

›Shelter

›Correctional facility

›Prior treatment and adherence

›Topical agent used and timing

›Repeat dosing interval

›Contacts treated concurrently

Host Risk Factors

›Crusted scabies risk

›Immunosuppression

›Neurologic disease with reduced itch perception

›Elderly frailty

›Pregnancy and lactation status

›Gestational age

›Breastfeeding

›Medication and allergy history

›Topical pyrethroid reactions

›Drug eruption history

03Physical Exam/exam27

Skin Distribution and Morphology

›Typical distribution

›Finger webs

›Flexor wrists

›Axillae

›Periumbilical region

›Waistline and belt area

›Genital involvement

›Typical lesions

›Burrows as thin serpiginous lines

›Erythematous papules

›Nodules in groin or axillae

›Pediatrics distribution

›Scalp involvement

›Palms and soles involvement

›Diffuse truncal eruption

Complications and Severity

›Secondary infection signs

›Honey crusting

›Pustules

›Cellulitis

›Crusted scabies signs

›Thick scale and crust

›Nail dystrophy and subungual debris

›Widespread plaques

›Mimic clues

›Annular plaques with central clearing

›Greasy scale on scalp and face

›Linear vesicles with plant exposure pattern

04Differential Diagnosis/ddx18

Pruritic Dermatoses

›Eczematous disorders

›Atopic dermatitis ICD-10 L20

›Allergic contact dermatitis ICD-10 L23

›Infestations and arthropods

›Pediculosis ICD-10 B85

›Bedbug bites SNOMED CT concept

›Urticarial disorders

›Acute urticaria ICD-10 L50

›Dermatographism SNOMED CT concept

Infectious and Inflammatory Mimics

›Viral exanthems

›Gianotti Crosti syndrome SNOMED CT concept

›Varicella zoster ICD-10 B01 or B02

›Fungal infections

›Tinea corporis ICD-10 B35

›Candidiasis intertrigo ICD-10 B37

›Drug related eruptions

›Morbilliform drug eruption SNOMED CT concept

›Fixed drug eruption SNOMED CT concept

05Laboratory Tests/lt18

When Labs Matter

›Labs for complication risk

›Complete blood count for systemic infection concern

›Leukocytosis supporting bacterial complication

›Eosinophilia nonspecific and not diagnostic

›C reactive protein for severe cellulitis concern

›Trend support for response

›Poor specificity for scabies itself

›Labs for immunocompromise context

›HIV testing when clinically indicated

›Higher crusted scabies risk with advanced disease

›Concurrent STI screening per exposure history

Microbiology for Superinfection

›Skin swab or culture when purulence present

›Staphylococcus aureus identification

›MRSA risk stratification per local epidemiology

›Antibiotic selection guidance

›Streptococcus pyogenes consideration

›Impetigo association

›Post streptococcal complications counseling

06Diagnostic Tests/dt31

Scoring Systems

›IACS scabies criteria framework

›Confirmed scabies category

›Mites or eggs or feces on microscopy

›Mite visualized on dermoscopy

›Clinical scabies category

›Burrows

›Typical lesions in typical distribution with supportive history

›Suspected scabies category

›Typical lesions with partial supportive features

›Exposure history without confirmatory testing

MRI

›MRI role

›Not indicated for routine scabies diagnosis

›No diagnostic utility for mites or burrows

›Avoid as workup for uncomplicated pruritus

›If invasive soft tissue infection concern, then MRI per cellulitis protocol

›Necrotizing infection concern triggers

›Deep abscess evaluation when ultrasound nondiagnostic

›CT role

›Not indicated for routine scabies diagnosis

›No diagnostic utility for mites

›Radiation risk without benefit

›If orbital or deep neck infection concern, then CT per site specific protocol

›Facial cellulitis extension concern

›Airway compromise concern

Ultrasound

›Bedside applications

›POCUS for abscess versus cellulitis when secondary infection suspected

›Fluid collection with posterior enhancement

›Cobblestoning for cellulitis

›Skin evaluation adjuncts

›High frequency ultrasound research use for burrows

›Not standard of care for routine diagnosis

07Disposition/dispo14

Outpatient Management

›Discharge appropriate features

›Stable vital signs

›No rapidly spreading cellulitis

›Reliable access to treatment and laundering

›Follow up planning

›Primary care follow up within 1 to 2 weeks if persistent symptoms

›Dermatology follow up for diagnostic uncertainty or refractory disease

Admission and Transfer

›Admission indications

›Crusted scabies with inability to self care

›Severe secondary bacterial infection requiring IV antibiotics

›Outbreak control needs in facility setting

›Transfer considerations

›Dermatology not available and crusted scabies severe

›Infection prevention resources required for unit level containment

08Treatment/t62

First Line Therapy

›Topical permethrin 5 percent regimen

›Application coverage

›Neck down including interdigital spaces

›Under nails and skin folds

›Scalp and face included for infants and elderly when involved

›Contact time

›Leave on 8 to 14 hours

›Wash off after interval

›Repeat dose

›Second application at 7 to 14 days

›Household treatment synchronized

Oral Therapy

›Ivermectin oral regimen

›Dose

›200 micrograms per kg per dose

›Take with food to improve bioavailability

›Uncomplicated scabies schedule

›Day 1 dose

›Day 8 dose

›Crusted scabies schedule options

›Day 1 dose

›Day 2 dose

›Day 8 dose

›Day 9 dose

›Day 15 dose

›Contraindications and cautions

›Pregnancy avoidance preference

›Weight under 15 kg avoidance preference

›Significant drug interaction review

Crusted Scabies Combination Protocol

›Combined topical and systemic approach

›Ivermectin intensive schedule per severity

›Multi dose regimen with day 1 to 2 and day 8 to 15 pattern

›Extend to day 22 and day 29 for severe burden per specialist plan

›Permethrin 5 percent frequent application

›Daily for 7 days

›Then 2 times weekly until cure

›Keratolytic adjuncts

›Salicylic acid preparations for scale reduction

›Urea cream for hyperkeratosis

›Environmental decontamination emphasis

›Linen handling with gloves

›Dedicated room and minimized staff contact

Symptom Control and Complications

›Post scabetic pruritus management

›Oral nonsedating antihistamine options

›Cetirizine standard dosing per age

›Loratadine standard dosing per age

›Topical anti inflammatory therapy

›Low to mid potency topical corticosteroid short course

›Emollients for barrier repair

›Secondary bacterial infection treatment

›Topical mupirocin for localized impetigo

›Three times daily for 5 days typical course

›Culture guidance if MRSA risk

›Oral antibiotics for extensive impetigo or cellulitis

›Cephalexin standard adult dosing per local guideline

›MRSA active agent when risk high per local guideline

›Evidence level mapping for practice

›Permethrin topical as first line supported by high quality evidence and guideline consensus

›Class I recommendation for typical scabies in most guidelines

›ACEP Level C style consensus for ED management pathways

›Ivermectin oral effective alternative and adjunct

›Class IIa recommendation for refractory or outbreak settings

›Class I recommendation for crusted scabies combination therapy under specialist guidance

09Special Populations/sp34

Pregnancy

›Pregnancy safe options

›Permethrin 5 percent preferred

›Minimal systemic absorption

›Repeat dosing at 7 to 14 days

›Sulfur ointment as alternative when permethrin not tolerated

›Odor and staining limitations

›Multiple day application protocols vary

›Pregnancy avoidance options

›Ivermectin generally avoided due to limited human pregnancy data

›Risk benefit individualized for crusted scabies

›Obstetrics consultation for severe disease

Geriatric

›Older adult considerations

›Higher crusted scabies risk with debility

›Atypical low itch despite high burden

›Nail involvement common

›Application assistance needs

›Caregiver training for full body coverage

›Facility wide coordination for contact treatment

›Comorbidity and polypharmacy review

›Ivermectin interaction screen

›Sedating antihistamine fall risk avoidance

Pediatrics

›Infant and child considerations

›Distribution differences

›Scalp and face involvement more common in infants

›Palms and soles involvement

›Topical permethrin use

›Age appropriate labeling and local guideline alignment

›Caregiver application instructions

›Ivermectin limits

›Avoidance preference under 15 kg

›Specialist input for severe or refractory cases

›School and daycare counseling

›Treatment completion before return per local policy

›Close contact notification

10Background/b33

Epidemiology

›Burden and distribution

›Global prevalence high with periodic outbreaks

›Higher rates in crowded settings

›Endemicity in many regions

›Risk clusters

›Household transmission common

›Institutional outbreaks significant

›Crusted scabies epidemiology

›Rare but highly contagious

›Associated with immunosuppression and frailty

Pathophysiology

›Mite lifecycle and symptoms

›Female mite burrows in stratum corneum

›Egg deposition in burrows

›Larvae mature over days

›Immune reaction drives itch and rash

›Sensitization delay in first infestation

›Faster symptoms in reinfestation

›Crusted scabies mechanism

›Impaired host response permits massive mite proliferation

›Thick hyperkeratosis increases fomite shedding

Therapeutic Considerations

›Treatment principles

›Two dose strategy for typical scabies

›First dose kills mites

›Second dose targets newly hatched mites

›Contact management critical

›Simultaneous treatment prevents reinfestation

›Asymptomatic contacts often infested

›Environmental control

›Wash clothing and bedding hot cycle when possible

›Seal non washable items in plastic for several days per guidance

›Persistent itch after cure

›Post inflammatory pruritus may last weeks

›Avoid repeated scabicide dosing without objective failure evidence

11Patient Discharge Instructions/pdi19

copy discharge instructions

›Scabies care plan

›Permethrin treatment completed as prescribed

›Second treatment date scheduled 7 to 14 days after first

›All household and close contacts treated same day

›Itching expectations

›Itch can last 2 to 4 weeks after successful treatment

›Moisturizer and anti itch medicines per plan

›Home cleaning

›Clothing and bedding used in last 3 days washed hot and dried hot

›Non washable items sealed in plastic bag for several days

›Return for urgent care if

›Fever

›Rapidly spreading redness

›Increasing pain or swelling

›Pus or new blisters

›Worsening weakness or confusion

›Follow up

›Recheck if new burrows or new lesions after 2 treatments

›Dermatology referral if symptoms persist beyond 4 weeks or diagnosis uncertain

12References/r8

Clinical Guidelines and Key Sources

›Guideline sources

›CDC scabies clinical guidance and treatment recommendations

›American Academy of Dermatology scabies guidance

›International Alliance for the Control of Scabies consensus criteria

›Evidence summaries

›Comparative efficacy studies for permethrin versus ivermectin

›Crusted scabies combination therapy evidence and outbreak control literature

›Infection prevention recommendations for institutional outbreaks

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Reviewed by SymptomDx Medical Team · Last reviewed June 16, 2026

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