Ask
- Itching, scratching
- Rash — hidden by clothing or on private part
- Other family members with scabies
- Anyone in family or community with crusted scabies — possible source of infection
- Always consider this for children or elderly people with frequent presentations
Check
- Calculate age-appropriate REWS
- Adult — AVPU, RR, O2 sats, pulse, BP, Temp
- Child (less than 13 years) — AVPU, respiratory distress, RR, O2 sats, pulse, central capillary refill time, Temp
- Weight, BGL
Do
- If infected sores — treat as for impetigo (school sores) at same time as treating scabies
Do — treat with topical permethrin 5% OR oral ivermectin
- Tell person itching may last for 1–4 weeks after treatment with permethrin or ivermectin
- ALSO treat all household members, close contacts and people who have had close physical
contact (eg person holding child with scabies) with permethrin 5% cream
For topical permethrin 5% cream
- In clinic demonstrate whole-body application of thin layer
- Adults and children — leave on for at least 8 hours. Best overnight under clean bed
clothes
- Babies under 6 months — leave on for 6–8 hours
- Repeat treatment in 1 week to kill any new mites that hatch after first application
Applying scabies creams or lotions
- Put on clean, dry skin — best at night before bed and left on for at least 8 hours
under clean pyjamas or clothes
- Apply to whole body including scalp and face and behind ears — avoid eyes, lips, mouth.
- If hair very thick or infestation very bad — may need to shave head. Always get permission
from person/carer
- Work carefully down whole body. Always include between fingers and toes, soles of
feet, under nails AND body creases — behind ears, under jaw, neck, armpits, back, bottom, groin, under
breasts AND joints and joints creases — elbows, knees, heels
- Advise to put cream on hands again after washing and put on child’s hands again before
bed
For ivermectin — give oral single dose with food (doses)
- Do not give to children under 5 years or less than 15kg OR women who are or could be pregnant or are breastfeeding — do urine pregnancy test
if not sure or no contraception
- Repeat in 7–14 days to kill any new mites that hatch
Prevention
- Encourage hand washing and short finger nails
- Ask family to wash clothes and sheets with laundry detergent and dry in sun and to
air blankets and mattresses in full sun
- Bed linen and sheets, towels and clothes that cannot be washed can be decontaminated
by placing in a sealed plastic bag for at least 8 days — scabies eggs will hatch mites
which will die
- Home visit to look for and treat other people with scabies or crusted scabies — may
be source of infection
Do — if difficult case or treatment failure
- 2 or more presentations of scabies where
- Permethrin 5% cream application or oral ivermectin has not worked
- AND reinfection unlikely because child treated properly/in clinic, repeat application
of cream applied or repeat dose of ivermectin has been given and all contacts treated
- If severe scabies affecting a lot of skin and person sick — medical consult
Step 1
Whole-body application of benzyl benzoate 25% lotion — see applying scabies creams and lotions
- Child under 6 months — do not use
- Child 6–23 months — dilute with 3 parts water
- Child 2–12 years and adults with sensitive skin — dilute with equal part water
- Occasionally causes severe skin irritation — usually resolves in 15 minutes
- Test on small area of skin first — wait for 10 minutes
- If severe reaction — dilute with equal part water for adults. Do not use for children
- Leave on for 24 hours
Step 2
Repeat topical treatment in 1 week — whole body application of benzyl benzoate 25% lotion as in Step 1
Follow-up
- Make sure second dose of treatment has been given
- After 7 days for topical permethrin 5% cream or benzyl benzoate lotion — applied in clinic if required
- After 7–14 days for oral ivermectin
- Return to clinic 3 weeks after second dose of treatment completed to check response
- If person has scabies often — consider
- Was cream/lotion applied properly
- Did whole family/household get treated
- Did everyone get second treatment
- Is there someone with crusted scabies
- Is it hard to maintain good hygiene at home — washing facilities and household cleaning
- Less common skin conditions that need review
- Make sure anyone in community with crusted scabies gets treatment as a high priority
— unless they are treated, contacts will keep getting scabies
- If a lot of scabies in community — consider community healthy skin program
- Where prevalence of scabies is assessed as 10% or higher consider an ivermectin-based
mass drug administration (MDA) program
- Talk with primary care team, PHU and infectious disease specialist
Crusted scabies
- Severe type of scabies caused by same mite — not sores from infected scabies. Person’s
immune system can’t control number of mites, so thousands of mites and very infectious
- High risk of serious bacterial infection in more severe cases. Lifelong risk of recurrence,
reduced life expectancy — manage as a chronic conditions
- Can involve 'shame' and social isolation — take care to be culturally sensitive
Check
- Look for thickened, scaly skin patches — may be 1–2 areas (eg bottom, hands, feet,
shoulders) or may cover whole body with thick/flaky crust
- Scale may have distinctive creamy colour, even in dark skinned people
- Can look like tinea, psoriasis, eczema, dermatitis, impetigo (school sores) with a
crust
- Often not itchy
Do not
- Do not confuse crusted scabies with severe scabies (with or without crusted skin sores)
or tinea
Do
For each episode
- Blood for FBC, UEC, LFT, CRP, HbA1c and blood cultures
- Skin scrapings — scabies microscopy, fungal culture. Use to confirm diagnosis and for notification
to PHU
- If associated with impetigo (school sores) — collect swab for MC&S
- If associated with nail disease — collect nail clippings for fungal growth
Diagnosis
- If crusted scabies suspected — urgent medical consult as soon as possible
- Can be difficult to diagnosis — must discuss with specialist
- Must notify confirmed cases — based on laboratory finding of scabies mites on scraping AND infectious disease specialist or dermatologist consult of in person, via photos (with
consent) or videoconference
- May consider if not done previously — blood for HIV (repeat if ongoing risk), HTLV-1, ANA, IgE/immunoglobulin, T-cell subsets
- If ANA positive take blood for dsDNA, ENA, C3, C4
Always talk with PHU or infectious diseases specialist
- Confirmed cases get public health response via clinic with contact tracing and treatment
of household and close contacts
- Most people with crusted scabies need to be sent to hospital
- People with Grade 2 or Grade 3 always send to hospital
- Some people with mild Grade 1 can be managed in community in consult with infectious
diseases unit or specialist scabies service
Grade severity
- Choose best option in each category and add numbers to get score — Table 7.32
- Assessment should always be made in consultation with PHU/infectious diseases specialist
A — Distribution and extent of crusting
- Wrists, web spaces, feet only — less than 10% of total body surface area (TBSA)
- As above PLUS forearms, lower legs, buttocks, trunk OR 10–30% TBSA
- As above PLUS scalp OR more than 30% TBSA
B — Crusting/shedding
- Mild crusting (less than 5mm deep), minimal skin shedding
- Moderate crusting (5–10mm deep), moderate skin shedding
- Severe crusting (more than 10mm deep), profuse skin shedding
C — Past episodes
- Never had it before
- Already been in hospital 1–3 times for crusted scabies OR depigmentation of elbows, knees
- Already been in hospital 4 or more times for crusted scabies OR depigmentation of elbows, knees, legs/back OR residual skin thickening or scaly skin
D — Skin conditions
- No cracking or pyoderma (pus in skin)
- Any of — multiple pustules, weeping sores, superficial skin cracking
- Deep skin cracking with bleeding, widespread purulent exudates (pussy fluids)
Score of grade severity
4–6 = Grade 1 |
7–9 = Grade 2 |
10–12 = Grade 3 |
Do not
Do not treat patients with Grade 2 or 3 crusted scabies in the community — for all suspected cases talk with PHU/infectious diseases specialist
Do — Grade 1 infection only
Can trial community management in consult with infectious diseases unit or specialist
scabies service. Frequent clinical supervision needed — best with directly observed
therapy (DOT)
- Give ivermectin oral once a day on days 0, 1, 7 — doses
- Do not give to children under 5 years or less than 15kg OR women who are or could be pregnant or are breastfeeding — do urine pregnancy test
if not sure or no contraception
- Whole-body application of topical agent — see applying scabies creams or lotions
- Put on dry skin after soaking and scrubbing skin in bath or shower
- Apply every second day for first week THEN twice a week until cured
- Benzyl benzoate 25% lotion
- Child under 6 months — do not use
- Child 6–23 months — dilute with 3 parts water
- Child 2–12 years and sensitive adults — dilute with equal parts water
- Occasionally causes severe skin irritation — usually resolves in 15 minutes
- Test on small area of skin first — leave for 10 minutes
- If severe reaction — dilute with equal part water for adults. Do not use for children
- Leave on for 24 hours
- OR permethrin 5% cream — if benzyl benzoate not available or not tolerated
- Leave on for at least 8 hours (overnight)
- Use lactic acid and urea cream every second day to soften skin — use on different
day to scabies cream
Treating family and house
- Aim to make household a ‘scabies-free zone’ to protect person from reinfection after
treatment
- Educate person and family about what this means, includes treatment for visitors so
person who gets crusted scabies can avoid reinfection
- Treat all household members, family and close contacts for scabies with permethrin 5% cream
- Work with hospital to ensure person not discharged home before all contracts treated
- Ask family to make sure that while having treatment with topical permethrin cream
or oral ivermectin they
- Wash underwear, bed clothes, towels and bed linen on hot 60*C wash cycle
- Take mattresses, blankets and doonas outside or hang on the washing line in full sunlight
for 72 hours
- Vacuum and sweep floor and soft furnishings to remove skin particles
- Sensitive management of household is needed due to stigma and chronic nature of disease
Long-term follow-up of crusted scabies
Secondary prevention
For people getting recurrent crusted scabies or with high risk of re-exposure, eg
living in house with young children
- Give supervised whole-body application of topical treatment preferably with benzyl benzoate lotion — every 2–4 weeks for 6 months THEN review
- If reinfection — infectious disease specialist consult about management
- Treat early before crusts form
Review
- At 2 weeks and 4 weeks after discharge THEN every 4 weeks to check skin for signs of reinfection — especially hands, shoulders,
bottom
- Moisturise daily to keep skin soft, eg sorbolene
- Regular reviews and early treatment if reinfected — important to break cycle of scabies
transmission and community outbreaks
- Lifelong follow-up is needed while living in scabies endemic area
Develop chronic care management plan
- High risk of reinfection
- Need good communication between acute and primary care providers
- Provide ongoing education — important that person and family understand
- About crusted scabies
- What they can do to self-manage
- Importance of a 'scabies-free zone'