Allergic Reaction or Atopy: The elevated absolute eosinophils (653) is highly suggestive of an allergic reaction or atopic condition such as asthma, atopic dermatitis, or allergic rhinitis. The slightly elevated absolute monocytes could be a secondary response to the allergic condition.

Parasitic Infection: Eosinophilia can be a hallmark of parasitic infections, especially those caused by helminths (worms). The elevated monocytes might indicate a concurrent inflammatory response.
Viral Infection: Certain viral infections can cause eosinophilia and monocytosis. For example, some respiratory viruses can lead to an increase in both eosinophils and monocytes.
Drug Reaction: Some medications can cause eosinophilia and monocytosis as part of a drug reaction. This could be an adverse effect of a recently introduced medication.

Leukemia (e.g., Acute Lymphoblastic Leukemia, ALL, or Acute Myeloid Leukemia, AML): Although less likely, leukemia must be considered in the differential diagnosis of any child with abnormal blood cell counts, including elevated monocytes and eosinophils. Leukemia can present with a wide range of blood abnormalities.
Lymphoma: Similar to leukemia, lymphoma can cause abnormal blood cell counts and should not be missed due to its serious implications.

Histiocytosis: A group of rare diseases involving abnormal proliferation of histiocytes, which can lead to elevated monocytes and eosinophils among other symptoms.
Churg-Strauss Syndrome (Eosinophilic Granulomatosis with Polyangiitis, EGPA): A rare autoimmune condition characterized by asthma, high levels of eosinophils, and vasculitis, which could explain the elevated eosinophils and possibly the monocytosis.
Hyperosinophilic Syndrome (HES): A rare disorder characterized by the overproduction of eosinophils, which can lead to organ damage. The elevated absolute eosinophils in this patient could be indicative of HES, although other diagnostic criteria would need to be met.