Approach to Scabies

key points:

1. Usually present with intense itching
2. Caused by Sarcoptes scabiei. The female mite burrows beneath the skin in order to lay eggs. The eggs hatch into tiny mites and spread out over the skin and live for only about 30 days
3. The mite antigen, in its excreta, causes a hypersensitivity rash.
4. Diagnosis is by microscopic examination of skin scrapings or by response to treatment
5. Usually spread through close contacts. Children need to be kept away from school until they complete the course of treatment.
6. According to therapeutic guideline, the treatment of choice is permethrin 5% leave on for at least 8 hours or benzyl benzoate for 24 hrs repeat after 1 week. Usually permethrin is better tolerated and less drying.
7. In kids less than 6 months, the current recommendation from therapeutic guideline is still permethrin 5 % but it also stated that permethrin is currently not licensed to be used for this purpose.
8. Other treatment for children under 6 months: sulphur 10%in white paraffin once daily for 2-3 days or chromatin 10% topically once daily for 2 -3 days
9. In immunocompromised patients, it can become crusted scabies, essentially means huge number of mites in the body known as norwegian scabies. Try to get expert opinion, treat with ivermectin 200 mcg/kg as a single dose plus topical treatment.

References:
John murtagh 5th edition
eTG