How can you tell them apart?
| Feature | Milia | Miliaria |
|---|---|---|
| What is trapped | Keratin inside small cysts. | Sweat behind blocked sweat ducts. |
| Appearance | Tiny white or yellow bumps beneath the skin. | Clear blisters, red bumps or, less commonly, deeper skin coloured bumps. |
| Sensation | Usually no pain or discomfort; some uncommon types itch. | The common red form is very itchy; other forms can have no symptoms. |
| Typical location | Face, especially eyelids, cheeks and nose. | Head, neck, trunk and skin folds, including areas rubbed by clothing. |
| Main approach | Allow time to clear, or discuss removal if bothersome. | Reduce sweating, heat and skin irritation. |
| Expected course | Weeks in newborns; weeks to months or longer in adults. | Usually clears within a day or two in a cooler environment. |
Colour alone is not enough to identify the bumps. Miliaria crystallina causes clear, fragile blisters that resemble beads of sweat. Miliaria rubra is the common itchy red form. The rare deeper form, miliaria profunda, causes skin coloured bumps. A clinician can usually identify either condition by examining the skin.23
What should you do for milia?
Milia are not acne or whiteheads, and they are not contagious. Treatment is optional because the cysts are harmless and often disappear without intervention. A treatment plan can involve no product at all, an arrangement the skincare aisle rarely advertises.13
- 1Wash daily with warm water and gentle soap, then pat dry rather than rubbing.
- 2Leave the bumps intact. Squeezing, scraping or picking milia can cause infection or permanent scarring.
- 3If the bumps bother you or persist, discuss treatment with a healthcare provider. Options include professional extraction, freezing and topical retinoids, medicines related to vitamin A.
Professional extraction involves opening the cyst with a sterile needle or blade and removing its contents. Topical retinoids may help widespread milia. Extensive cases can also be treated with procedures such as chemical peels or laser treatment. These are options for removing unwanted cysts, not a necessary routine for every white bump.1
Milia can also develop while damaged skin heals, including after burns or blistering rashes. Some occur after heavy creams or ointments, and some are associated with topical medicines. Minimise further skin injury, and do not use prescribed steroid creams longer than directed.13
What should you do for miliaria?
- 1Move to a cooler environment and sleep in a cool, ventilated room.
- 2Remove excess or tight clothing. Choose breathable fabrics and change out of wet clothes.
- 3Use cool water compresses or a cool bath, and avoid excessive soap and other irritants.
Most heat rash settles within a day or two after cooling. Calamine can relieve discomfort but is drying. Medical treatment can include mild topical steroids or treatment for a secondary bacterial infection. Severe or repeated episodes need assessment; heat rash can interfere with the body's ability to regulate temperature.2
What if the bumps are on a baby?
Both conditions occur in newborns. Neonatal milia often appear on the nose and clear within a few weeks of birth. Do not apply adult lotions or oils to a baby's delicate skin. For heat rash, avoiding overheating, removing excess clothing and cool baths are useful measures.134
When should you get medical help?
Arrange an appointment if suspected milia worsen or do not improve after a few months. A newborn who seems ill and has blisters or pus filled spots needs assessment for infection. If you are worried about your baby's rash, contact their healthcare provider promptly.345
Get urgent medical advice for a baby under 3 months with a temperature of 38C or higher. Seek emergency help for a child with a rash and difficulty breathing, unusual unresponsiveness, or bruise like spots that do not fade when pressed with a glass.6
Where this answer comes from
- 1Milium, miliadermnetnz.org
- 2Heat rash (Miliaria): Images, Causes, and Treatmentdermnetnz.org
- 3Milia (Milk Spots): Causes & Treatmentmy.clevelandclinic.org
- 4Newborn Skin: Part I. Common Rashesaafp.org
- 5Common Infant and Newborn Problems: MedlinePlusmedlineplus.gov
- 6Rashes in babies and childrennhs.uk
