Scab is due to bacterial skin disease..known as ecthyma
It is streptococcal infection
There is thick crust,which does not removed easily.
Poor hygiene,poor nutrition,immunodeficiencies might be resposible ..
You should be thoroughly examined and investigated by expert to rule out internal diseases.
To remove crust, you may do as below ...
Soak a clean cloth in a mixture of half a cup of white vinegar in a litre of tepid water. Apply the compress to moist areas for about ten minutes several times a day. Gently wipe off the crusts.
Antibiotics like penicillin or dicloxacillin
may be used.
Anti inflammatory drugs may be taken.
oint to enhance the response.
Clean the area with antiseptic .
You may be benefitted, take treatment under supervision of dermatologist
I hop you got my answer.
Dr. Ilyas Patel MD