A one-month-old baby with a lot of small pimples on his face may be due to prickly heat, eczema, acne and other factors, you can choose to adjust your life, medication and other ways to alleviate. 1. prickly heat: for one-month baby, may be because of the hot and humid environment in summer, often wearing non-breathable clothing, it is very easy to cause sweat ducts clogged, there are a lot of small pimples symptoms, belong to the manifestation of prickly heat, as far as possible to keep the skin cool and dry, and at the same time, to wear loose and breathable cotton clothing, you can topical glycerine lotion therapy. 2. eczema: one month baby face a lot of small pimples, may also be related to eczema, especially one month baby skin is relatively weak, in the case of skin water content is reduced, sebum content is reduced, as well as genetic factors, eczema symptoms, you can use glycerine lotion, hydrocortisone and other coated treatment. 3. Acne: Infantile acne, the cause of which is unclear, may be caused by an increase in androgen secretion at birth. The appearance of a lot of small pimples on the face, you need to pay attention to skin cleanliness, at the same time can be applied to the compound cypress liquid or fusidic acid cream anti-infection treatment. All of the above medications should be used under the guidance of a doctor, avoid self-medication to avoid adverse effects.