Thanks for the query,
Appearance of bumps on body with scab can happen even in internal disorders, like psoriasis
It is not necessary that some thing should come in contact with body to cause skin lesion.
Apply some antibacterial cream to prevent infection.
may be required to confirm diagnosis.
Please meet a dermatologist
for final diagnosis and treatment
Let me know if you have any other doubt.
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Wishing you a good health.