Atopic Dermatitis (Eczema): This is the most likely diagnosis given the symptoms of pruritus (itching) and small bumps all over the body, particularly in a child. Atopic dermatitis is a common condition in children, characterized by dry, itchy skin and is often associated with other atopic diseases like asthma and allergies.

Insect Bites or Allergic Reaction: The presence of small bumps and intense itching could also suggest an allergic reaction to insect bites, which is common in children who spend time outdoors.
Contact Dermatitis: This condition occurs when the skin comes into contact with an irritant or allergen, leading to a rash and itching. It's possible the child came into contact with something that triggered this reaction.
Scabies: Although less likely without a clear history of exposure, scabies can cause intense itching and a rash, and it's highly contagious.

Bullous Pemphigoid: A rare autoimmune disease that can cause blistering of the skin and intense itching. Although rare in children, it's crucial to consider due to its potential severity.
Meningococcemia: In rare cases, a rash can be a sign of a more serious infection like meningococcemia, especially if the child had been in contact with someone with the infection. The absence of fever does not rule this out entirely, as some cases can present atypically.

Kawasaki Disease: This condition mainly affects children and can cause a rash, among other symptoms. However, it typically includes fever, which is not present in this case.
Urticaria Pigmentosa (Mastocytosis): A rare condition where mast cells accumulate in the skin, causing itching, hives, and sometimes small bumps. It's less common in children but should be considered in cases of chronic itching without an obvious cause.
Erythema Multiforme: A skin condition characterized by target lesions, which can sometimes be itchy. It's often triggered by infections or medications.