Keratin Bumps (Milia)

What is Keratin Bumps (Milia)?

Milia are tiny, hard, white‑to‑pearly bumps that appear on the skin’s surface. They are filled with keratin – a protein that makes up hair, nails, and the outer layer of skin. Because the keratin becomes trapped just beneath the outermost skin layer (the stratum corneum), a small cyst forms that looks like a tiny “whitehead.” Milia are most common on the face (especially around the eyes, cheeks, and forehead) but can also occur on the scalp, neck, chest, and even the genital area.

In most cases milia are benign and painless, and they often resolve on their own within a few weeks to months. However, when they become numerous, persist for a long time, or are associated with other skin changes, it is worth evaluating the underlying cause.

Common Causes

While milia can appear spontaneously, they are frequently linked to a specific trigger or underlying condition. Below are the most frequently reported causes (listed alphabetically):

• Damage to the skin barrier – burns, blistering disorders, or excessive exfoliation can trap keratin under the surface.
• Heavy or comedogenic skin‑care products – ointments, moisturizers, or sunscreen that are too thick can occlude pores.
• Genetic predisposition – some people inherit a tendency to develop milia, especially in families with certain dermatologic conditions.
• Infancy – newborns often have milia due to immature skin and the presence of vernix caseosa.
• Medication side effects – topical steroids, retinoids, or certain systemic drugs (e.g., phenytoin) can alter keratinization.
• Photodamage – chronic sun exposure damages the skin’s ability to shed keratin normally.
• Skin diseases that affect keratinisation – e.g., xerosis, ichthyosis, or seborrheic dermatitis.
• Trauma or surgical procedures – skin grafts, laser resurfacing, dermabrasion, or chemical peels can leave “secondary” milia.
• Underlying systemic conditions – rare associations with conditions such as basal cell nevus syndrome or certain genetic disorders.
• Obstructive keratin plugs – frequent in adults with “primary” milia that arise without any apparent skin injury.

Associated Symptoms

Milia themselves are usually asymptomatic, but a few related findings may accompany them, especially when linked to an underlying skin disorder:

• Dry, flaky skin (xerosis)
• Redness or mild irritation around the bumps
• Other types of comedones (blackheads or whiteheads)
• Scaling or crusting if a secondary infection occurs
• In infants, a “mattress‑like” pattern of bumps on the face, often called “milial rash.”

When to See a Doctor

Most milia do not require urgent medical attention, but you should schedule an appointment if you notice any of the following:

• The bumps become painful, swollen, or warm – signs of infection.
• Rapid increase in number or size.
• Persistent milia that do not resolve after 6–12 months.
• Associated skin changes such as persistent redness, scaling, or ulceration.
• Presence of milia alongside other concerning lesions (e.g., pigmented growths, persistent acne nodules, or signs of skin cancer).
• For infants: if the bumps are accompanied by fever, poor feeding, or other systemic symptoms.

Diagnosis

Diagnosis of milia is primarily clinical—performed by a dermatologist or primary‑care provider through visual inspection. The typical steps include:

1. History taking – onset, duration, any recent skin procedures, product use, or medical conditions.
2. Physical examination – milia appear as 1‑2 mm, dome‑shaped, flesh‑colored or white papules with a smooth surface.
3. Dermatoscopy (optional) – a handheld magnifier may reveal a central keratin core.
4. Skin biopsy (rare) – performed if the lesion looks atypical or if a different diagnosis such as basal cell carcinoma is suspected.

Laboratory testing is not usually required unless an underlying systemic disease is suspected.

Treatment Options

Because milia often resolve spontaneously, many clinicians adopt a “watch‑and‑wait” approach. When treatment is desired, options fall into three categories: topical, procedural, and home‑care measures.

Topical Therapies

• Retinoids – topical tretinoin, adapalene, or tazarotene stimulate skin turnover and can help clear existing keratin plugs. Use under medical supervision, as retinoids may cause irritation.
• Alpha‑hydroxy acids (AHAs) – glycolic or lactic acid creams exfoliate the surface, reducing the chance of new milia forming.
• Keratolytic ointments – containing salicylic acid (0.5–2%) can loosen keratin. Not recommended for infants.

Procedural Treatments

• Manual extraction – A dermatologist uses a sterile needle or comedone extractor to gently press the bump, releasing the keratin core. This technique should not be attempted at home to avoid scarring.
• Cryotherapy – Freezing the lesion with liquid nitrogen can cause it to shed, though it is rarely needed for typical milia.
• Laser therapy – CO₂ or Er:YAG laser resurfacing can remove multiple milia after cosmetic procedures.
• Chemical peels – Medium‑depth peels (e.g., trichloroacetic acid 20–30%) are effective after post‑procedure milia appear.

Home‑Care Measures

• Gentle, non‑comedogenic cleansing twice daily.
• Avoid heavy ointments or oil‑based sunscreens; choose “non‑acnegenic” or “water‑based” sunscreens.
• Exfoliate lightly with a soft washcloth or a chemical exfoliant (AHA/BHA) no more than 2–3 times per week.
• Do not pick or squeeze the bumps; this can cause infection or scarring.
• Apply a thin layer of over‑the‑counter (OTC) retinol after a short acclimation period (start with 0.25% every third night).

Prevention Tips

Preventing milia focuses on maintaining a healthy skin barrier and avoiding occlusive products that trap keratin. Here are evidence‑based strategies:

• Choose non‑comedogenic skin‑care – Look for labels that say “oil‑free” or “won’t clog pores.”
• Use gentle cleansers – Avoid harsh soaps that strip natural oils and trigger compensatory keratin buildup.
• Protect skin from sun – Broad‑spectrum sunscreen (SPF 30 or higher) applied daily reduces photodamage that predisposes to milia.
• Limit excessive exfoliation – Over‑scrubbing can damage the stratum corneum, increasing the risk of keratin entrapment.
• After cosmetic procedures – Follow post‑procedure care instructions precisely; use recommended moisturizers and avoid heavy creams for the first weeks.
• Monitor medication side effects – Discuss with a dermatologist if a prescribed topical steroid or retinoid seems to worsen milia.
• For infants – Gentle baby washes and avoiding scented or oil‑heavy lotions reduce the likelihood of congenital milia.

Emergency Warning Signs

Key Take‑aways

Milia are tiny keratin‑filled cysts that are usually harmless and self‑limited. Knowing the common triggers—such as heavy skin products, skin injury, or sun damage—helps you choose preventive measures. Most cases improve with gentle skin‑care, occasional topical retinoids, or professional extraction. Seek medical evaluation if the lesions become painful, infected, or persistent, or if any emergency warning signs develop.

References:

• Mayo Clinic. “Milia.” Accessed May 2026. https://www.mayoclinic.org/diseases-conditions/milia
• American Academy of Dermatology. “Milia (Keratin Cysts).” 2024. https://www.aad.org/public/diseases/a-z/milia
• National Institutes of Health – MedlinePlus. “Milia.” Updated 2023. https://medlineplus.gov/ency/article/001076.htm
• Cleveland Clinic. “How to Treat Milia.” 2024. https://my.clevelandclinic.org/health/diseases/16021-milia
• Dermatology journals: S. Kwon et al., “Management of Post‑Procedure Milia,” *Journal of Cosmetic Dermatology*, 2022.