Symptoms |
Pubic or genital itch (especially at night with scabies) &/or rash |
Scabies: genital papulonodule |
Crabs: debris in underwear |
Complications |
Scabies:Complications uncommon and mostly in crusted scabies (institutionalised)
|
Pubic lice: fever, lethargy, irritability (more common in the young and frail) |
See STI Atlas for more images.
Scabies:
Pubic lice:
Test | Site/Specimen |
---|---|
Crabs: direct visualisation +/- magnification of crab or nits (egg) |
Adult lice infest strong hairs (pubic hair, eyebrows and eyelashes). |
Scabies: usually a clinical diagnosis. |
Characteristic nodule and silvery skin burrows sometimes seen e.g. nodule on glans penis and scrotum concurrently, labial fold nodule, burrows (inter-digital folds, wrists and elbows, around breast nipples in women). |
Crabs:
Scabies:
Scabies:
Principal Treatment Options | ||
---|---|---|
Situation | Recommended | Alternative |
Scabies |
Apply permethrin cream 5% topically to dry skin from the neck down, paying particular attention to hands and genitalia, and under the nails with a nailbrush. Leave on the skin for a minimum of 8 hours (usually overnight) and reapply to hands if they are washed. |
Apply benzyl benzoate 25% emulsion topically to dry skin from the neck down, paying particular attention to hands and genitalia, and under the nails with a nailbrush. Leave on for 24 hours and reapply to hands if they are washed. |
Pubic lice |
Apply permethrin 1% cream rinse to pubic and other hair infested with lice and wash off after 10 minutes. |
Bioallethrin with piperonyl butoxide. |
Crusted scabies (formerly called Norwegian scabies) occurs when the mite population is very high due to poor host immune response, such as people with HIV infection, and also in remote Indigenous communities. Seek specialist advice for treatment.
Scabies:
Pubic lice:
Consider seeking specialist advice before treating any complicated or persisting presentation.
Situation | Recommended |
---|---|
Complicated or disseminated infection |
For less severe crusted scabies, use ivermectin 200mcg/kg PO, on day 1, and second dose between day 8-14. An additional dose maybe required for moderate–severe scabies, but seek specialist advice. If secondary bacterial infection (impetigo) is severe, pre-treat with antibiotics to cover S. aureus and/or S. pyogenes before administering anti-scabetic treatment. |
Persistent infection |
Ivermectin 200mcg/kg PO, on days 1 and 8-14, not before 4 weeks after failure of both topical Permethrin and Benzyl Benzoate. |
Pregnant women ![]() |
Permethrin is safe in pregnancy and during breast feeding. |
Allergy to principal treatment choice |
Seek specialist advice. |
Regional/Remote |
No special differences. Scabies may affect entire small remote communities where a whole community treatment regimen may be required. Seek local advice. |
Eye lash infestation | Permethrin 1% lotion keeping the eyes closed during the 10 min application. Ophthalmic-grade petrolatum ointment bd 10 days (prescription needed and compounding pharmacist to make). |
Scabies:
Pubic lice:
Review in 1 week provides an opportunity to:
Not required.
Not required but provides an opportunity to consider testing for other STIs, if not undertaken at first presentation, or retesting post the window period.
If itch and rash persist, reassurance and anti-pruritics (as above) may be helpful.