Pls understand, that Keratosis Pilaris is not a disease. It's a normal variant of skin condition that runs in families. It's present in around 50% of total population and is completely normal. The only problem you face is cosmetically.
You can answer your friends or relatives, that the doctor has adviced it's completely normal and no need to treat it. And it doesn't spread from one person to other.
Regarding cure: it's a condition which is very difficult to treat. So, the treatment response varies from 0% to 80% and also varies from patient to patient. Complete cure is usually not attained.
Next Steps
Online/physical consultation from a dermatologist is adviced if you have problem cosmetically. or else treatment is not required.
Health Tips
DO NOT rub, scratch and squeeze the lesions which will infect the lesions.