Hi, welcome to the forum, child’s symptoms are suggestive of atopic or
allergic dermatitis, secondary
to exposure
to allergen and mediated by IgE antibodies. His body is known to hypersensitive to certain things. Stinging insects, Aeroallergens (uncommon), Foods and additives like Milk, egg, peanuts, nuts, soy, and wheat are the most common agents to cause such dermatitis in children.
This triggering factor should be identified and should be avoided. A skin allergy test can be useful.