I would like to know how I can differentiate their everyday eczema from an allergic reaction?

To differentiate between everyday eczema and an allergic reaction in a child, you can look for certain signs. Eczema is a type of allergy, but usually milder. If a child already has severe eczema or eczema all over their body, it may be due to exposure to an allergen. In the case of an allergic reaction, the eczema patches may become more pronounced. In severe reactions, the child may experience a sudden worsening of eczema symptoms.