Hi. Thanks for posting your concern at HCM.
Scabies is transmitted by prolonged close contact and can be transmitted from one person to another in the family. If your in laws have scabies then it is very possible that other members residing with them could also have been infected.
If any one in the family has scabies it is usually advisable to treat the whole family empirically.
Scabies can involve genital areas, thighs , abdomen, trunk, arms,
axilla etc. Itching is classically more severe at night.
Treatment is simple. I advice my patients of scabies a single, whole body application(sparing face) of 5% permethrin cream/lotion for 8 hrs (overnight), which is curative in most cases.
All the family members should be treated simultaneously.
An oral antihistamine like
cetrizine would help with the itching associated with it.
It is important to wash all the clothes, bed-sheets, pillow covers, towels and handkerchiefs etc.
take care
regards