My baby has red spots on back and tummy
Insect bite hypersensitivity
Hello and welcome to ask a doctor service. I have viewed the image and gone through the query.
They seem to be like mosquito bites/ bug bites I suggest you to use a soothing lotion e.g calamine lotion over the affected area, 2-3 times a day. You can also give syp. hydroxyzine to relieve itching.
Hope I have answered your query. Let me know if you need any more assistance.
Regarding red patches and bumps on skin
Perhaps those small bumps are due to excessively dry skin/ xerosis. I suggest you to use a moisturizer daily e.g Aquaphor/ petrolatum and the red patches that I see could also possibly be Hives instead of insect bites.