Milia: Symptoms, Types, Causes and Treatment

Milia are tiny, often stubborn cysts that can appear on the skin at any age, causing confusion, cosmetic concern, and questions about their origin and management. Whether you’ve noticed a few pearly bumps on a newborn’s cheek, or clusters of cysts on an adult’s eyelids, understanding milia is key to effective treatment and peace of mind. In this article, we’ll explore the symptoms, types, causes, and treatment of milia, using up-to-date research to guide you through this common but often misunderstood skin condition.

Symptoms of Milia

Milia are most often noticed as small, painless bumps on the skin—yet their appearance and location can vary widely. Recognizing the typical symptoms is the first step toward proper identification and management.

Appearance	Location	Sensation	Source(s)
Small, dome-shaped, pearly or yellowish-white papules (1–2 mm)	Most often on the face, especially eyelids, cheeks, and sometimes genitalia	Usually asymptomatic (no pain or itch); occasionally mild redness in special forms	2, 3, 4, 9

Table 1: Key Symptoms

What Do Milia Look Like?

Milia are commonly described as tiny, dome-shaped bumps that are white or yellowish in color. They typically measure 1–2 mm in diameter and have a smooth, hard surface. Seen up close, milia resemble “pearls” embedded just beneath the skin surface 3, 4, 9.

• Classic milia: Isolated or scattered, non-inflamed bumps
• Milia en plaque: Multiple milia grouped within a mildly red, raised patch or plaque, often near the ears or eyelids 2, 10
• Eruptive milia: Sudden appearance of numerous lesions, often on the face, neck, or trunk 4

Where Do Milia Appear?

Milia most frequently occur on the face—especially around the eyes (eyelids), cheeks, and sometimes the forehead. In newborns, they are especially common on the nose and upper trunk 3, 4. Milia can also appear on other sites, such as the genitalia, neck, or sites of trauma or previous skin disease 4, 7, 9.

Do Milia Cause Discomfort?

Most people with milia report no symptoms aside from their visible appearance. The bumps are typically painless and not itchy. However, in rare forms like milia en plaque, the surrounding skin may be mildly red or inflamed 2, 10. The main concern for many is cosmetic.

Types of Milia

Milia are not all the same. They are classified into several types based on their origin, appearance, and associated conditions. Knowing the type can guide understanding and treatment.

Type	Key Features	Population / Setting	Source(s)
Primary	Spontaneous, on healthy skin	Newborns, children, adults	3, 4, 7
Secondary	After skin injury/disease	Any age, post-trauma	3, 4, 7, 9
Milia en plaque	Grouped in red plaque	Adults, peri-auricular/eyelid	2, 10, 12, 13
Eruptive milia	Sudden, numerous lesions	Elderly, juveniles	4
Syndromic/genetic	Associated with genodermatoses	Rare, syndromic cases	1, 3, 4, 9

Table 2: Milia Types Overview

Primary Milia

Primary milia develop spontaneously without preceding skin trauma or disease. They are especially prevalent in newborns, where they commonly appear on the face and upper trunk. In adults, primary milia are most often found on the eyelids, cheeks, and occasionally the genitalia 3, 4.

Secondary Milia

Secondary milia arise following skin damage or disease. This includes trauma (like burns, dermabrasion, or radiotherapy), prolonged use of topical steroids, or after the healing of blistering or inflammatory skin conditions such as bullous pemphigoid, epidermolysis bullosa, or lichen planus 3, 4, 7, 8, 9. They tend to localize to the area of injury or disease.

Milia en Plaque

This rare form features multiple milia grouped within an erythematous (red), slightly raised plaque. Milia en plaque usually appears on the face, especially around the ears or eyelids, and can be a cosmetic concern 2, 10, 12, 13. The cause is often unclear, but trauma or topical agents may play a role in some cases.

Eruptive Milia

Eruptive milia are characterized by the rapid onset of multiple lesions in a short period (usually within a month). They may affect the head, neck, or trunk and can occur in both elderly individuals and children 4. The cause is often unknown, though rare genetic forms exist.

Syndromic or Genetic Milia

Some rare syndromes and genetic skin diseases (genodermatoses) include milia as a feature. Examples are Rombo syndrome, basaloid follicular hamartoma syndrome, and Gardner syndrome 1, 3, 4, 9.

Causes of Milia

Understanding why milia form is crucial for prevention and management. Their causes are multifactorial, ranging from developmental quirks in newborns to injury or disease in adults.

Cause / Trigger	Mechanism	Examples / Settings	Source(s)
Developmental	Spontaneous formation from hair follicles	Newborns, adults (primary milia)	3, 4, 6, 7, 9
Trauma / Injury	Damage to skin structures	Burns, dermabrasion, radiotherapy	3, 4, 7, 9, 12
Inflammatory Disease	Abnormal skin repair	Bullous diseases, lichen planus	7, 8, 9
Drugs / Topicals	Skin atrophy or irritation	Long-term corticosteroids, 5-FU	3, 7, 14
Genetic Syndromes	Abnormal skin development	Rombo, Gardner, etc.	1, 3, 4, 9
Unknown / Spontaneous	No clear cause	Eruptive milia, milia en plaque	4, 10, 12

Table 3: Causes and Triggers of Milia

How Do Milia Form?

• Primary milia are thought to originate from the sebaceous collar of vellus hair follicles, particularly on the face and eyelids. In other body areas, milia may develop from eccrine (sweat) ducts or the epidermis 3, 4, 7, 9.
• Secondary milia form when keratin (the main protein in skin) becomes trapped beneath the outer layer during healing from injury, trauma, or inflammation. This can occur after burns, blistering diseases, or excessive topical steroid use 3, 4, 7, 9.

Common Triggers and Associations

• Skin Injury: Any trauma that disrupts the epidermis can lead to milia. This includes:
  • Burns (thermal, chemical, or sunburn)
  • Dermabrasion or laser procedures
  • Radiotherapy 3, 4, 7, 9, 12
• Blistering and Inflammatory Skin Diseases:
  • Epidermolysis bullosa, bullous pemphigoid, porphyria cutanea tarda, and lichen planus can all be followed by milia formation, especially during healing 7, 8, 9.
• Drugs and Topicals:
  • Prolonged use of topical corticosteroids, 5-fluorouracil, or certain anti-inflammatory drugs can induce milia by causing skin atrophy or irritation 3, 7, 14.
• Genetic/Syndromic Causes:
  • Some rare genetic disorders include milia as part of their skin manifestations 1, 3, 4, 9.
• Idiopathic/Unknown:
  • In many cases, especially in eruptive milia or milia en plaque, no specific cause can be identified 4, 10, 12.

Treatment of Milia

While milia are harmless and often resolve on their own, treatment may be desired for cosmetic reasons or if lesions are persistent. Treatment options range from simple extraction to advanced dermatological procedures.

Treatment	Indication	Effectiveness / Notes	Source(s)
Manual extraction	Isolated lesions	Highly effective, immediate result	10, 14
Topical retinoids	Multiple lesions	Promotes exfoliation, slow-acting	10, 14
Chemical peels	Extensive/facial milia	Partial to marked improvement	10, 14
CO₂ laser	Resistant, grouped milia	Good cosmetic outcomes, safe	12, 14
Dermabrasion	Milia en plaque, extensive	Complete regression in some cases	13, 14
No treatment	Asymptomatic, transient	Often resolves spontaneously	4, 10

Table 4: Milia Treatment Options

When Is Treatment Needed?

Most milia do not require treatment and may resolve spontaneously—especially in infants or after transient skin injury 4, 10. Treatment is generally considered if milia are:

• Persistent or widespread
• Causing cosmetic concern
• Associated with discomfort or irritation

Common Treatment Modalities

Manual Extraction

A dermatologist can remove milia safely using a sterile needle or blade to open the cyst and extract its contents. This is effective for isolated lesions, but not practical for widespread milia 10, 14.

Topical Retinoids

Retinoid creams (like tretinoin) can be prescribed to promote exfoliation of the skin, helping to clear and prevent formation of new milia. This is particularly helpful for multiple or recurrent lesions, but effects may take weeks 10, 14.

Chemical Peels

Superficial chemical peels using agents like glycolic or salicylic acid can help in cases with multiple facial milia. They accelerate exfoliation and may improve cosmetic appearance 10, 14.

CO₂ Laser and Dermabrasion

For resistant or grouped milia, such as milia en plaque, CO₂ laser vaporization and dermabrasion have shown high rates of success with minimal side effects 12, 13, 14. These treatments are usually performed by dermatologists and provide good cosmetic results.

Other Treatments

• Photodynamic therapy: Has been reported as partially effective in some cases of milia en plaque 10.
• Oral medications: Rarely, drugs like minocycline have been tried for specific cases of milia en plaque, with variable results 11.
• No treatment / Observation: For asymptomatic or transient milia, no intervention is necessary 4, 10.

Conclusion

Milia are common, benign keratin-filled cysts that can affect people of all ages. While usually harmless, their appearance can cause cosmetic distress and confusion with other skin conditions. Here’s what to remember:

• Symptoms: Milia are small, dome-shaped, white or yellowish bumps, most often on the face and eyelids. They are typically painless and asymptomatic 2, 3, 4, 9.
• Types: Milia are classified as primary, secondary, eruptive, milia en plaque, and syndromic/genetic, based on their origin and associations 1, 2, 3, 4, 10.
• Causes: They can arise spontaneously, after skin injury, as a result of inflammatory or blistering skin diseases, with certain medications, or as part of rare syndromes 3, 4, 7, 8, 9, 14.
• Treatment: Most milia resolve on their own, but persistent lesions can be treated effectively with manual extraction, topical retinoids, chemical peels, CO₂ laser, or dermabrasion 10, 12, 13, 14.

In summary:

• Milia are generally harmless and often self-limited.
• Accurate diagnosis and classification are essential for appropriate management.
• A range of safe and effective treatments are available for those bothered by their appearance.
• Consultation with a dermatologist is recommended for extensive, recurrent, or atypical cases.

Understanding milia empowers patients and clinicians to make informed decisions—ensuring both skin health and peace of mind.