Scabies

What to consider in Primary Care before referring:

General Comments

• Human scabies is an infestation of the skin caused by the mite Sarcoptesscabiei.

• The mites are most readily transmitted from one person to another by close physical contact in a warm atmosphere i.e., sharing a bed, holding hands, adults tending to children, children playing with each other

• An individual who has never had scabies before may not develop itching or a rash until one month to three months after becoming infested.

• There is usually
  Widespread inflammatory papular eruption
  Burrows on non hair bearing skin of the extremities
  Pruritic papules around the axilla, nipples, umbilical region and buttocks
  Inflammatory nodules on the penis and scrotum

• The reactive rash to scabies can be eczematous or urticarial - Impetiginisation may also occur.

• Usually more than one family member is affected.

• It is mandatory that all members of the household and any other close social contacts of an infested person should receive treatment at the same time as the patient.

Treatment in primary care

• Treat patients when there is a strong clinical suspicion that they may be infested.

• If unsure whether eczema or scabies, treat eczema first and review.

• The first and essential step is to kill all the mites in the skin using a scabicide.

Scabicide

• Apply either:
  Permethrin 5% (Lyclear Dermal Cream)
  Malathion 0.5% Aqueous solution (Derbac M)

• Rub it in to all parts of the body.

• Treat all the skin other than the face.

• Remove rings and use a nail brush to apply under the nails.

• Remind patients to re-apply the scabicide after washing their hands.

• Malathion should be left on the skin for 24 hours and Permethrin for between 8–12 hours.

• At the end of this period the patients can bath, change their underclothes, nightclothes, sheets and pillowcases.

• Disinfestation of clothing and bedding other than by ordinary laundering is not necessary.

• One treatment is probably curative but a second application after 1 week is recommended.

• If these directions have been followed, all mites in the skin will have been killed but the pruritus may take 3–6 weeks to settle.

• Do not keep using scabicides as repeated applications may irritate the skin.

• Treat residual itchy areas with:
  Topical anti-pruriticCrotamiton cream (Eurax)
  Crotamiton/hydrocortisone (Eurax HC)

• A higher potency of steroid may be needed to treat areas of secondary eczema

Referral Threshold

• Diagnostic uncertainty

• Failure of response to treatment